1,625 research outputs found
Electron and ion microprobe analysis of calcium distribution and transport in coral tissues.
It is shown by x-ray microanalysis that a gradient of total intracellular Ca concentration exists from the outer oral ectoderm to the inner skeletogenic calicoblastic ectoderm in the coral Galaxea fascicularis. This suggests an increase in intracellular Ca stores in relation to calcification. Furthermore, Ca concentration in the fluid-filled space of the extrathecal coelenteron is approximately twice as high as in the surrounding seawater and higher than in the mucus-containing seawater layer on the exterior of the oral ectoderm. This is indicative of active Ca2+ transport across the oral epithelium. Polyps were incubated in artificial seawater in which all 40Ca was replaced by 44Ca. Imaging Ca2+ transport across the epithelia by secondary ion mass spectroscopy (SIMS) using 44Ca as a tracer showed that Ca2+ rapidly entered the cells of the oral epithelium and that 44Ca reached higher concentrations in the mesogloea and extrathecal coelenteron than in the external seawater layer. Very little Ca2+ was exchanged in the mucocytes, cnidocytes or zooxanthellae. These observations again suggest that Ca2+ transport is active and transcellular and also indicate a hitherto unsuspected role in Ca2+ transport for the mesogloea. © 2007, Company of Biologist
The multi-modal nature of trustworthiness perception
Most past work on trustworthiness perception has focused on the structural features of the human face. The present study investigates the interplay of dynamic information from two channels – the face and the voice. By systematically varying the level of trustworthiness in each channel, 49 participants were presented with either facial or vocal information, or the combination of both, and made explicit judgements with respect to trustworthiness, dominance, and emotional valence. For most measures results revealed a primacy effect of facial over vocal cues. In examining the exact nature of the trustworthiness - emotion link we further found that emotional valence functioned as a significant mediator in impressions of trustworthiness. The findings extend previous correlational evidence and provide important knowledge of how trustworthiness in its dynamic and multi-modal form is decoded by the human perceiver. Index Terms: trustworthiness, face, voice, emotion, dynamic, multi-moda
A realtime observatory for laboratory simulation of planetary flows
Motivated by the large-scale circulation of the atmosphere and ocean, we develop a system that uses
observations from a laboratory analog to constrain, in real time, a numerical simulation of the laboratory
flow. This system provides a tool to rapidly prototype new methods for state and parameter
estimation, and facilitates the study of prediction, predictability, and transport of geophysical fluids
where observations or numerical simulations would not independently suffice.
A computer vision system is used to extract measurements of the physical simulation. Observations
are used to constrain the model-state of the MIT General Circulation Model in a probabilistic, ensemble based assimilation approach. Using a combination of parallelism, domain decomposition and an efficient
scheme to select ensembles of model-states, we show that estimates that effectively track the fluid state
can be produced. To the best of our knowledge this is the first such observatory for laboratory
analogs of planetary circulation that functions in real time.National Science Foundation (U.S.) (CNS-0540259)National Science Foundation (U.S.) (grant CNS-0540248
Vocal and facial trustworthiness of talking heads
Trust is a key aspect to human communication due to its link to co-operation and survival. Recent research by [Ballew and Todorov 2007] has shown that humans can generate an initial trustworthiness judgement based on facial features within 100ms. However, in that work, perceived trustworthiness has been studied solely in the context of facial information. It has been suggested by [Surawski and Ossoff 2006] that trustworthiness cues are also prevalent in the auditory channel. There is however, no prior empirical evidence to suggest that visual cues are more important than audio cues and how people deal with inconsistent cues between the audio and visual channels
A voz dos utilizadores dos cuidados de saúde primários da região de Lisboa e Vale do Tejo, Portugal
Visualizing Natural Image Statistics
Natural image statistics is an important area of research in cognitive sciences and computer vision. Visualization of statistical results can help identify clusters and anomalies as well as analyze deviation, distribution and correlation. Furthermore, they can provide visual abstractions and symbolism for categorized data. In this paper, we begin our study of visualization of image statistics by considering visual representations of power spectra, which are commonly used to visualize different categories of images. We show that they convey a limited amount of statistical information about image categories and their support for analytical tasks is ineffective. We then introduce several new visual representations, which convey different or more information about image statistics. We apply ANOVA to the image statistics to help select statistically more meaningful measurements in our design process. A task-based user evaluation was carried out to compare the new visual representations with the conventional power spectra plots. Based on the results of the evaluation, we made further improvement of visualizations by introducing composite visual representations of image statistics
Cyclooxygenase activity mediates colorectal cancer cell resistance to the omega-3 polyunsaturated fatty acid eicosapentaenoic acid
Purpose
The naturally-occurring omega-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) is safe, well-tolerated and inexpensive, making it an attractive anti-cancer intervention. However, EPA has only modest anti-colorectal cancer (CRC) activity, when used alone. Both cyclooxygenase (COX) isoforms metabolise EPA and are over-expressed in CRC cells. We investigated whether COX inhibition increases the sensitivity of CRC cells to growth inhibition by EPA.
Methods
A panel of 18 human and mouse CRC cell lines was used to characterize the differential sensitivity of CRC cells to the growth inhibitory effects of EPA. The effect of CRISPR-Cas9 genetic deletion and pharmacological inhibition of COX-1 and COX-2 on the anti-cancer activity of EPA was determined using in vitro and in vivo models.
Results
Genetic ablation of both COX isoforms increased sensitivity of CT26 mouse CRC cells to growth inhibition by EPA in vitro and in vivo. The non-selective COX inhibitor aspirin and the selective COX-2 inhibitor celecoxib increased sensitivity of several human and mouse CRC cell lines to EPA in vitro. However, in a MC38 mouse CRC cell tumour model, with dosing that mirrored low-dose aspirin use in humans, thereby producing significant platelet COX-1 inhibition, there was ineffective intra-tumoral COX-2 inhibition by aspirin and no effect on EPA sensitivity of MC38 cell tumours.
Conclusion
Cyclooxygenase inhibition by non-steroidal anti-inflammatory drugs represents a therapeutic opportunity to augment the modest anti-CRC activity of EPA. However, intra-tumoral COX inhibition is likely to be critical for this drug-nutrient interaction and careful tissue pharmacodynamic profiling is required in subsequent pre-clinical and human studies
The Classic: A Morphogenetic Matrix for Differentiation of Bone Tissue
This Classic Article is a reprint of the original work by Marshall R. Urist, A Morphogenetic Matrix for Differentiation of Bone Tissue. An accompanying biographical sketch of Marshall R. Urist, MD is available at DOI 10.1007/s11999-009-1067-4; a second Classic Article is available at DOI 10.1007/s11999-009-1068-3; and a third Classic Article is available at DOI 10.1007/s11999-009-1069-2. The Classic Article is © 1970 by Springer and is reprinted with permission from Urist MR. A morphogenetic matrix for differentiation of bone tissue. Calc Tiss Res. 1970:4(Suppl);98–101
Estradiol and testosterone levels in patients undergoing partial hepatectomy - A possible signal for hepatic regeneration?
In five adult male patients undergoing a 40-60% partial hepatectomy, serum sex hormone levels before and after hepatic resection were determined. Blood was drawn immediately prior to each surgical procedure and at specified time points postoperatively. Compared to hormone levels found prior to surgery, following major hepatic resection, estradiol levels increase at 24 and 48 hr, while testosterone levels decline, being significantly reduced at 96 and 144 hr. These data demonstrate that adult males who undergo a 40-60% partial hepatectomy experience alterations in their sex hormone levels similar to those observed in male rats following a 70% hepatectomy. These changes in sex hormone levels have been associated in animals with an alteration of the sex hormone receptor status of the liver that is thought to participate in the initiation of the regenerative response. These studies suggest, but do not prove, that in man, as in the case of the rat, sex hormones may participate in the initiation of or at least modulate in part the regenerative response that occurs following a major hepatic resection. © 1989 Plenum Publishing Corporation
Social research on neglected diseases of poverty: Continuing and emerging themes
Copyright: © 2009 Manderson et al.Neglected tropical diseases (NTDs) exist and persist for social and economic reasons that enable the vectors and pathogens to take advantage of changes in the behavioral and physical environment. Persistent poverty at household, community, and national levels, and inequalities within and between sectors, contribute to the perpetuation and re-emergence of NTDs. Changes in production and habitat affect the physical environment, so that agricultural development, mining and forestry, rapid industrialization, and urbanization all result in changes in human uses of the environment, exposure to vectors, and vulnerability to infection. Concurrently, political instability and lack of resources limit the capacity of governments to manage environments, control disease transmission, and ensure an effective health system. Social, cultural, economic, and political factors interact and influence government capacity and individual willingness to reduce the risks of infection and transmission, and to recognize and treat disease. Understanding the dynamic interaction of diverse factors in varying contexts is a complex task, yet critical for successful health promotion, disease prevention, and disease control. Many of the research techniques and tools needed for this purpose are available in the applied social sciences. In this article we use this term broadly, and so include behavioral, population and economic social sciences, social and cultural epidemiology, and the multiple disciplines of public health, health services, and health policy and planning. These latter fields, informed by foundational social science theory and methods, include health promotion, health communication, and heath education
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