375 research outputs found

    Auditory grouping occurs prior to intersensory pairing: evidence from temporal ventriloquism

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    The authors examined how principles of auditory grouping relate to intersensory pairing. Two sounds that normally enhance sensitivity on a visual temporal order judgement task (i.e. temporal ventriloquism) were embedded in a sequence of flanker sounds which either had the same or different frequency (Exp. 1), rhythm (Exp. 2), or location (Exp. 3). In all experiments, we found that temporal ventriloquism only occurred when the two capture sounds differed from the flankers, demonstrating that grouping of the sounds in the auditory stream took priority over intersensory pairing. By combining principles of auditory grouping with intersensory pairing, we demonstrate that capture sounds were, counter-intuitively, more effective when their locations differed from that of the lights rather than when they came from the same position as the lights

    No effect of auditory–visual spatial disparity on temporal recalibration

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    It is known that the brain adaptively recalibrates itself to small (∼100 ms) auditory–visual (AV) temporal asynchronies so as to maintain intersensory temporal coherence. Here we explored whether spatial disparity between a sound and light affects AV temporal recalibration. Participants were exposed to a train of asynchronous AV stimulus pairs (sound-first or light-first) with sounds and lights emanating from either the same or a different location. Following a short exposure phase, participants were tested on an AV temporal order judgement (TOJ) task. Temporal recalibration manifested itself as a shift of subjective simultaneity in the direction of the adapted audiovisual lag. The shift was equally big when exposure and test stimuli were presented from the same or different locations. These results provide strong evidence for the idea that spatial co-localisation is not a necessary constraint for intersensory pairing to occur

    The Impact of Spatial Incongruence on an Auditory-Visual Illusion

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    The sound-induced flash illusion is an auditory-visual illusion--when a single flash is presented along with two or more beeps, observers report seeing two or more flashes. Previous research has shown that the illusion gradually disappears as the temporal delay between auditory and visual stimuli increases, suggesting that the illusion is consistent with existing temporal rules of neural activation in the superior colliculus to multisensory stimuli. However little is known about the effect of spatial incongruence, and whether the illusion follows the corresponding spatial rule. If the illusion occurs less strongly when auditory and visual stimuli are separated, then integrative processes supporting the illusion must be strongly dependant on spatial congruence. In this case, the illusion would be consistent with both the spatial and temporal rules describing response properties of multisensory neurons in the superior colliculus.status: publishe

    Oncolysis of malignant human melanoma tumors by Coxsackieviruses A13, A15 and A18

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    Many RNA viruses are displaying great promise in the field of oncolytic virotherapy. Previously, we reported that the picornavirus Coxsackievirus A21 (CVA21) possessed potent oncolytic activity against cultured malignant melanoma cells and melanoma xenografts in mice. In the present study, we demonstrate that three additional Group A Coxsackieviruses; Coxsackievirus A13 (CVA13), Coxsackievirus A15 (CVA15) and Coxsackievirus A18 (CVA18), also have similar oncolytic activity against malignant melanoma. Each of the viruses grew quickly to high titers in cancer cells expressing ICAM-1 and intratumoral injection of preformed subcutaneous SK-Mel-28 xenografts in mice with CVA13, CVA15 and CVA18 resulted in significant tumor volume reduction

    The Distances of the Magellanic Clouds

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    The present status of our knowledge of the distances to the Magellanic Clouds is evaluated from a post-Hipparcos perspective. After a brief summary of the effects of structure, reddening, age and metallicity, the primary distance indicators for the Large Magellanic Cloud are reviewed: The SN 1987A ring, Cepheids, RR Lyraes, Mira variables, and Eclipsing Binaries. Distances derived via these methods are weighted and combined to produce final "best" estimates for the Magellanic Clouds distance moduli.Comment: Invited review article to appear in ``Post Hipparcos Cosmic Candles'', F. Caputo & A. Heck (Eds.), Kluwer Academic Publ., Dordrecht, in pres

    Sound Frequency and Aural Selectivity in Sound-Contingent Visual Motion Aftereffect

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    BACKGROUND: One possible strategy to evaluate whether signals in different modalities originate from a common external event or object is to form associations between inputs from different senses. This strategy would be quite effective because signals in different modalities from a common external event would then be aligned spatially and temporally. Indeed, it has been demonstrated that after adaptation to visual apparent motion paired with alternating auditory tones, the tones begin to trigger illusory motion perception to a static visual stimulus, where the perceived direction of visual lateral motion depends on the order in which the tones are replayed. The mechanisms underlying this phenomenon remain unclear. One important approach to understanding the mechanisms is to examine whether the effect has some selectivity in auditory processing. However, it has not yet been determined whether this aftereffect can be transferred across sound frequencies and between ears. METHODOLOGY/PRINCIPAL FINDINGS: Two circles placed side by side were presented in alternation, producing apparent motion perception, and each onset was accompanied by a tone burst of a specific and unique frequency. After exposure to this visual apparent motion with tones for a few minutes, the tones became drivers for illusory motion perception. However, the aftereffect was observed only when the adapter and test tones were presented at the same frequency and to the same ear. CONCLUSIONS/SIGNIFICANCE: These findings suggest that the auditory processing underlying the establishment of novel audiovisual associations is selective, potentially but not necessarily indicating that this processing occurs at an early stage

    Echoes from Ancient Supernovae in the Large Magellanic Cloud

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    In principle, the light from historical supernovae could still be visible as scattered-light echoes even centuries later. However, while echoes have been discovered around some nearby extragalactic supernovae well after the explosion, targeted searches have not recovered any echoes in the regions of historical Galactic supernovae. The discovery of echoes can allow us to pinpoint the supernova event both in position and age and, most importantly, allow us to acquire spectra of the echo light to type the supernova centuries after the direct light from the explosion first reached the Earth. Here we report on the discovery of three faint new variable surface brightness complexes with high apparent proper motion pointing back to well-defined positions in the Large Magellanic Cloud (LMC). These positions correspond to three of the six smallest (and likely youngest) previously catalogued supernova remnants, and are believed to be due to thermonuclear (Type Ia) supernovae. Using the distance and proper motions of these echo arcs, we estimate ages of 610 and 410 yr for the echoes #2 and #3.Comment: 13 pages, 3 figures, 1 table. PDF format. Note: This paper has been accepted by Nature for publication as a letter. It is embargoed for discussion in the popular press until publication in Natur

    Correlation between MMPs and their inhibitors in breast cancer tumor tissue specimens and in cell lines with different metastatic potential

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    Background: The metastatic disease rather than the primary tumor itself is responsible for death in most solid tumors, including breast cancer. The role of matrix metalloproteinases ( MMPs), tissue inhibitors of MMPs (TIMPs) and Reversion-inducing cysteine-rich protein with Kazal motifs ( RECK) in the metastatic process has previously been established. However, in all published studies only a limited number of MMPs/MMP inhibitors was analyzed in a limited number of cell lines. Here, we propose a more comprehensive approach by analyzing the expression levels of several MMPs (MMP-2, MMP-9 and MMP-14) and MMP inhibitors (TIMP-1, TIMP-2 and RECK) in different models ( five human breast cancer cell lines, 72 primary breast tumors and 30 adjacent normal tissues). Methods: We analyzed the expression levels of MMP-2, MMP-9 and MMP-14 and their inhibitors (TIMP-1, TIMP-2 and RECK) by quantitative RT-PCR (qRT-PCR) in five human breast cancer cell lines presenting increased invasiveness and metastatic potential, 72 primary breast tumors and 30 adjacent normal tissues. Moreover, the role of cell-extracellular matrix elements interactions in the regulation of expression and activity of MMPs and their inhibitors was analyzed by culturing these cell lines on plastic or on artificial ECM (Matrigel). Results: The results demonstrated that MMPs mRNA expression levels displayed a positive and statistically significant correlation with the transcriptional expression levels of their inhibitors both in the cell line models and in the tumor tissue samples. Furthermore, the expression of all MMP inhibitors was modulated by cell-Matrigel contact only in highly invasive and metastatic cell lines. The enzyme/inhibitor balance at the transcriptional level significantly favors the enzyme which is more evident in tumor than in adjacent non-tumor tissue samples. Conclusion: Our results suggest that the expression of MMPs and their inhibitors, at least at the transcriptional level, might be regulated by common factors and signaling pathways. Therefore, the multi-factorial analysis of these molecules could provide new and independent prognostic information contributing to the determination of more adequate therapy strategies for each patient.`Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Pesquisa (CNPq)Financiadora de Estudos e Projetos (FINEP)Pro-Reitoria da Universidade de Sao Paulo (PRP-USP

    Speech and Non-Speech Audio-Visual Illusions: A Developmental Study

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    It is well known that simultaneous presentation of incongruent audio and visual stimuli can lead to illusory percepts. Recent data suggest that distinct processes underlie non-specific intersensory speech as opposed to non-speech perception. However, the development of both speech and non-speech intersensory perception across childhood and adolescence remains poorly defined. Thirty-eight observers aged 5 to 19 were tested on the McGurk effect (an audio-visual illusion involving speech), the Illusory Flash effect and the Fusion effect (two audio-visual illusions not involving speech) to investigate the development of audio-visual interactions and contrast speech vs. non-speech developmental patterns. Whereas the strength of audio-visual speech illusions varied as a direct function of maturational level, performance on non-speech illusory tasks appeared to be homogeneous across all ages. These data support the existence of independent maturational processes underlying speech and non-speech audio-visual illusory effects

    Factors associated with use of breast cancer screening services by women aged ≥ 40 years in Korea: The Third Korea National Health and Nutrition Examination Survey 2005 (KNHANES III)

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    <p>Abstract</p> <p>Background</p> <p>Despite evidence that breast cancer screening reduces morbidity and mortality, until recently most women have not undergone regular mammogram examinations in Korea. We aimed to identify factors associated with use of breast cancer screening services.</p> <p>Methods</p> <p>The Health Promotion Knowledge, Attitude and Practice survey (HP-KAP survey) is part of the Third Korea National Health and Nutrition Examination Survey 2005 (KNHANES III), a nationwide health survey in Korea. Of 7,802 individuals who participated in the HP-KAP survey, 4,292 were female. Of these, 2,583 were women aged at least 40 years and without a history of breast cancer; these women were included in this study. Information about breast cancer screening participation was obtained from the responses to questionnaires. The overall rate of regular breast cancer screening was measured. Factors that affect participation in a breast cancer screening program were identified using multiple logistic regression analysis.</p> <p>Results</p> <p>Among women aged at least 40 years, 30.4% complied with breast screening recommendations. Age of at least 65 years (adjusted odds ratio, aOR 0.61, 95% CI: 0.42-0.88), education level (no [ref], elementary school [aOR 1.51, 95% CI: 1.06-1.47], middle/high school [aOR 1.99, 95% CI: 1.36-2.92], university/higher [aOR 2.73, 95% CI: 1.71-4.35]), private health insurance (aOR 1.42, 95% CI: 1.71-4.35), attitude towards screening tests (aOR 0.18, 95% CI: 0.14-0.23), self-reported health status of 'fair' (aOR 1.26 95% CI: 1.00-1.58), and smoking (aOR 0.52, 95% CI: 0.35-0.79) were associated with the rate of regular breast cancer screening</p> <p>Conclusions</p> <p>To increase the nationwide breast cancer screening rate, more attention should be given to underrepresented groups, particularly the elderly, those with a low education level, smokers, and those with a negative attitude towards screening tests. These issues highlight the need for a new emphasis in health education, promotional campaigns and public health policy aimed at these underrepresented groups.</p
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