518 research outputs found
Distortions of Subjective Time Perception Within and Across Senses
Background: The ability to estimate the passage of time is of fundamental importance for perceptual and cognitive processes. One experience of time is the perception of duration, which is not isomorphic to physical duration and can be distorted by a number of factors. Yet, the critical features generating these perceptual shifts in subjective duration are not understood.
Methodology/Findings: We used prospective duration judgments within and across sensory modalities to examine the effect of stimulus predictability and feature change on the perception of duration. First, we found robust distortions of perceived duration in auditory, visual and auditory-visual presentations despite the predictability of the feature changes in the stimuli. For example, a looming disc embedded in a series of steady discs led to time dilation, whereas a steady disc embedded in a series of looming discs led to time compression. Second, we addressed whether visual (auditory) inputs could alter the perception of duration of auditory (visual) inputs. When participants were presented with incongruent audio-visual stimuli, the perceived duration of auditory events could be shortened or lengthened by the presence of conflicting visual information; however, the perceived duration of visual events was seldom distorted by the presence of auditory information and was never perceived shorter than their actual durations.
Conclusions/Significance: These results support the existence of multisensory interactions in the perception of duration and, importantly, suggest that vision can modify auditory temporal perception in a pure timing task. Insofar as distortions in subjective duration can neither be accounted for by the unpredictability of an auditory, visual or auditory-visual event, we propose that it is the intrinsic features of the stimulus that critically affect subjective time distortions
Zoonoses and information of the public: the role of media, with special reference to Italy
The significance of zoonoses varies depending
on many socio\u2010economic factors and on the
specific situation that prevails in a specific area.
The role of the media often determines the
importance given to a disease. In resource\u2010rich
countries, a zoonosis may be perceived as
being important due to inaccurate information
that has been circulated by mass media on the
risk of infection for animals and humans and
on the possible use of the agent for terrorist
actions. Images of sick or dead people and
animals, drastic methods of control and others,
can contribute to an overestimation of the
significance of a disease. Information can be
lacking or absent in regard to socio\u2010economic
factors that clarify occurrence and also on
geographic distribution. Therefore, the
sensitivity of people can be influenced rapidly
and negative socio\u2010economic consequences can
occur. These zoonoses can be named \u2018mediaoriented
(emphasised) zoonoses\u2019. On the
contrary, some zoonoses are scarcely
considered for several reasons, for instance:
occurrence in poverty\u2010stricken areas and
populations, risks of infection for people not
considered important enough to deserve
medical care, little interest from the media,
decision\u2010makers and health services, lack of
information and official reports. These
zoonoses can be named \u2018neglected zoonoses\u2019.
Some examples of zoonoses included in the
above categories are described
Dynamics of generalized PT-symmetric dimers with time-periodic gain–loss
A parity-time (PT)-symmetric system with periodically varying-in-time gain and loss modeled by two coupled Schrödinger equations (dimer) is studied. It is shown that the problem can be reduced to a perturbed pendulum-like equation. This is done by finding two constants of motion. Firstly, a generalized problem using Melnikov-type analysis and topological degree arguments is studied for showing the existence of periodic (libration), shift- periodic (rotation), and chaotic solutions. Then these general results are applied to the PT-symmetric dimer. It is interestingly shown that if a sufficient condition is satisfied, then rotation modes, which do not exist in the dimer with constant gain–loss, will persist. An approximate threshold for PT-broken phase corresponding to the disappearance of bounded solutions is also presented. Numerical study is presented accompanying the analytical results
Separate processing of texture and form in the ventral stream : evidence from fMRI and visual agnosia.
Real-life visual object recognition requires the processing of more than just geometric (shape, size, and orientation) properties. Surface properties such as color and texture are equally important, particularly for providing information about the material properties of objects. Recent neuroimaging research suggests that geometric and surface properties are dealt with separately, within the lateral occipital cortex (LOC) and the collateral sulcus (CoS), respectively. Here we compared objects that either differed in aspect ratio or in surface texture only, keeping all other visual properties constant. Results on brain-intact participants confirmed that surface texture activates an area in the posterior CoS, quite distinct from the area activated by shape within LOC. We also tested two patients with visual object agnosia, one of whom (DF) performed well on the texture task but at chance on the shape task, while the other (MS) showed the converse pattern. This behavioral double dissociation was matched by a parallel neuroimaging dissociation, with activation in CoS but not LOC in patient DF, and activation in LOC but not CoS in patient MS. These data provide presumptive evidence that the areas respectively activated by shape and texture play a causally necessary role in the perceptual discrimination of these features
European Red List of Habitats Part 1. Marine habitats
The European Red List of Habitats provides an overview of the risk of collapse (degree of endangerment) of marine, terrestrial and freshwater habitats in the European Union (EU28) and adjacent regions (EU28+), based on a consistent set of categories and criteria, and detailed data and expert knowledge from involved countries1. A total of 257 benthic marine habitat types were assessed. In total, 19% (EU28) and 18% (EU28+) of the evaluated habitats were assessed as threatened in categories Critically Endangered, Endangered and Vulnerable. An additional 12% were Near Threatened in the EU28 and 11% in the EU28+. These figures are approximately doubled if Data Deficient habitats are excluded. The percentage of threatened habitat types differs across the regional seas. The highest proportion of threatened habitats in the EU28 was found in the Mediterranean Sea (32%), followed by the North-East Atlantic (23%), the Black Sea (13%) and then the Baltic Sea (8%). There was a similar pattern in the EU28+. The most frequently cited pressures and threats were similar across the four regional seas: pollution (eutrophication), biological resource use other than agriculture or forestry (mainly fishing but also aquaculture), natural system modifications (e.g. dredging and sea defence works), urbanisation and climate change. Even for habitats where the assessment outcome was Data Deficient, the Red List assessment process has resulted in the compilation of a substantial body of useful information to support the conservation of marine habitats
Predicting future cancer burden in the United States by artificial neural networks
Aims: To capture the complex relationships between risk factors and cancer incidences in the US and predict future cancer burden. Materials & methods: Two artificial neural network (ANN) algorithms were adopted: a multilayer feed-forward network (MLFFNN) and a nonlinear autoregressive network with eXogenous inputs (NARX). Data on the incidence of the four most common tumors (breast, colorectal, lung and prostate) from 1992 to 2016 (available from National Cancer Institute online datasets) were used for training and validation, and data until 2050 were predicted. Results: The rapid decreasing trend of prostate cancer incidence started in 2010 will continue until 2018–2019; it will then slow down and reach a plateau after 2050, with several differences among ethnicities. The incidence of breast cancer will reach a plateau in 2030, whereas colorectal cancer incidence will reach a minimum value of 35 per 100,000 in 2030. As for lung cancer, the incidence will decrease from 50 per 100,000 (2017) to 31 per 100,000 in 2030 and 26 per 100,000 in 2050. Conclusion: This up-to-date prediction of cancer burden in the US could be a crucial resource for planning and evaluation of cancer-control programs
Effect of Different Percentage of Camelina sativa Cake in Laying Hens Diet: Performance, Welfare, and Eggshell Quality
Although camelina [Camelina sativa (L.) Crantz] is a good source of protein, antioxidants, and polyunsaturated fatty acids, its antinutritional compounds limit its use in animal feeding. The aim of this study was to verify the effect of feeding laying hens with up to 20% of camelina cake from a breeding line containing a low level of glucosinolates on performance, welfare, and eggshell quality. Two hundred and forty Hy-Line\uae hens from 18 to 51 weeks of age were divided into three treatments: control (C), camelina cake 10% (CAM10), and camelina cake 20% (CAM20). Egg number was recorded daily, while egg weight, feed consumption, and mortality were recorded weekly. At 24 and 43 weeks of hen age, shell resistance to fracture was measured. Our results demonstrate no detrimental effects for CAM10 and CAM20 diets on feed intake, growth performance, and welfare. No difference in egg production was detected among the diets. The significant (p < 0.05) interaction of diet and age factors suggest that the addition of camelina cake, up to 20%, likely protects the eggshell of older hens. Our findings confirm that camelina cake might be an alternative and sustainable protein source for hens
Extrapulmonary transport of MWCNT following inhalation exposure
Background
Inhalation exposure studies of mice were conducted to determine if multi-walled carbon nanotubes (MWCNT) distribute to the tracheobronchial lymphatics, parietal pleura, respiratory musculature and/or extrapulmonary organs. Male C57BL/6 J mice were exposed in a whole-body inhalation system to a 5 mg/m3 MWCNT aerosol for 5 hours/day for 12 days (4 times/week for 3 weeks, lung burden 28.1 ug/lung). At 1 day and 336 days after the 12 day exposure period, mice were anesthetized and lungs, lymph nodes and extrapulmonary tissues were preserved by whole body vascular perfusion of paraformaldehyde while the lungs were inflated with air. Separate, clean-air control groups were studied at 1 day and 336 days post-exposure. Sirius Red stained sections from lung, tracheobronchial lymph nodes, diaphragm, chest wall, heart, brain, kidney and liver were analyzed. Enhanced darkfield microscopy and morphometric methods were used to detect and count MWCNT in tissue sections. Counts in tissue sections were expressed as number of MWCNT per g of tissue and as a percentage of total lung burden (Mean ± S.E., N = 8 mice per group). MWCNT burden in tracheobronchial lymph nodes was determined separately based on the volume density in the lymph nodes relative to the volume density in the lungs. Field emission scanning electron microscopy (FESEM) was used to examine MWCNT structure in the various tissues. Results
Tracheobronchial lymph nodes were found to contain 1.08 and 7.34 percent of the lung burden at 1 day and 336 days post-exposure, respectively. Although agglomerates account for approximately 54% of lung burden, only singlet MWCNT were observed in the diaphragm, chest wall, liver, kidney, heart and brain. At one day post exposure, the average length of singlet MWCNT in liver and kidney, was comparable to that of singlet MWCNT in the lungs 8.2 ± 0.3 versus 7.5 ± 0.4 um, respectively. On average, there were 15,371 and 109,885 fibers per gram in liver, kidney, heart and brain at 1 day and 336 days post-exposure, respectively. The burden of singlet MWCNT in the lymph nodes, diaphragm, chest wall and extrapulmonary organs at 336 days post-exposure was significantly higher than at 1 day post-exposure. Conclusions
Inhaled MWCNT, which deposit in the lungs, are transported to the parietal pleura, the respiratory musculature, liver, kidney, heart and brain in a singlet form and accumulate with time following exposure. The tracheobronchial lymph nodes contain high levels of MWCNT following exposure and further accumulate over nearly a year to levels that are a significant fraction of the lung burden 1 day post-exposure
Pulmonary fibrotic response to aspiration of multi-walled carbon nanotubes
<p>Abstract</p> <p>Background</p> <p>Multi-walled carbon nanotubes (MWCNTs) are new manufactured nanomaterials with a wide spectrum of commercial applications. To address the hypothesis that MWCNTs cause persistent pulmonary pathology, C57BL/6J mice were exposed by pharyngeal aspiration to 10, 20, 40 or 80 μg of MWCNTs (mean dimensions of 3.9 μm × 49 nm) or vehicle. Lungs were preserved at 1, 7, 28 and 56 days post- exposure to determine the potential regions and target cells for impact by MWCNT lung burden. Morphometric measurement of Sirius Red staining was used to assess the connective tissue response.</p> <p>Results</p> <p>At 56 days post-exposure, 68.7 ± 3.9, 7.5 ± 1.9 and 22.0 ± 5.1 percent (mean ± SE, N = 8) of the MWCNT lung burden were in alveolar macrophages, alveolar tissue and granulomatous lesions, respectively. The subpleural tissues contained 1.6% of the MWCNT lung burden. No MWCNTs were found in the airways at 7, 28 or 56 days after aspiration The connective tissue in the alveolar interstitium demonstrated a progressive increase in thickness over time in the 80 μg exposure group (0.12 ± 0.01, 0.12 ± 0.01, 0.16 ± 0.01 and 0.19 ± 0.01 μm for 1, 7, 28 and 56 days post-exposure (mean ± SE, N = 8)). Dose-response determined at 56 days post-exposure for the average thickness of connective tissue in alveolar septa was 0.11 ± 0.01, 0.14 ± .02, 0.14 ± 0.01, 0.16 ± 0.01 and 0.19 ± 0.01 μm (mean ± SE, N = 8) for vehicle, 10, 20, 40 and 80 μg dose groups, respectively.</p> <p>Conclusions</p> <p>The distribution of lung burden was predominately within alveolar macrophages with approximately 8% delivery to the alveolar septa, and a smaller but potentially significant burden to the subpleural tissues. Despite the relatively low fraction of the lung burden being delivered to the alveolar tissue, the average thickness of connective tissue in the alveolar septa was increased over vehicle control by 45% in the 40 μg and 73% in the 80 μg exposure groups. The results demonstrate that MWCNTs have the potential to produce a progressive, fibrotic response in the alveolar tissues of the lungs. However, the increases in connective tissue per μg dose of MWCNTs to the interstitium are significantly less than those previously found for single-walled carbon nanotubes (SWCNTs).</p
Polymorphisms of microsomal epoxyde hydrolase gene and severity of HCV-related liver disease.
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