1,720,962 research outputs found
Skin wetness detection thresholds and wetness magnitude estimations of the human index fingerpad and their modulation by moisture temperature
No full textHumans often experience wet stimuli using their hands, yet we know little on how sensitive our fingers are to wetness and the mechanisms underlying this sensory function. We therefore aimed to quantify the minimum amount of water required to detect wetness on the human index fingerpad, the wetness detection threshold, and assess its modulation by temperature. Eight blinded participants (24.0 ± 5.2 y; 23.3 ± 3.5 BMI) used their index fingerpad to statically touch stimuli varying in volume (0, 10, 20, 30, 40 or 50 ml) and temperature (25, 29, 33 or 37 °C). During and post contact, participants rated wetness and thermal sensations using a modified yes/no task and a visual analogue scale. The wetness detection threshold at a moisture temperature akin to human skin (33 °C) was 24.7 ± 3.2ml. This threshold shifted depending on moisture temperature (P = 0.002), with cooler temperatures reducing (18.7 ± 3.9ml at 29 °C) and warmer temperatures increasing (27.0 ± 3.0ml at 37 °C) thresholds. When normalised over contact area, the wetness detection threshold at 33 °C corresponded to 1.926x10-4 ml mm-2 (95% CI: 1.873x10-4, 1.979x10-4 ml mm-2). Threshold differences were reflected by magnitude estimation data, which were analysed using linear regression to show that both volume and moisture temperature can predict magnitude estimations of wetness (P < 0.001). Our results indicate high sensitivity to wetness in the human index fingerpad, which can be modulated by moisture temperature. These findings are relevant for the design of products with wetness management properties.</p
The role of friction on skin wetness perception during dynamic interactions between the human index fingerpad and materials of varying moisture content
No full textMechanosensory inputs arising from dynamic interactions between the skin and moisture, such as when sliding a finger over a wet substrate, contribute to the perception of skin wetness. Yet, the exact relationship between the mechanical properties of a wet substrate, such as friction, and the resulting wetness perception remains to be established under naturalistic haptic interactions. We modeled the relationship between mechanical and thermal properties of substrates varying in moisture levels (0.49 × 10 -4; 1.10 × 10 -4; and 2.67 × 10 -4 mL·mm -2), coefficient of friction (0.783, 0.848, 1.033, 0.839, 0.876, and 0.763), and maximum thermal transfer rate ( Q max, ranging from 511 to 1,260 W·m -2·K -1), and wetness perception arising from the index finger pad's contact with such substrates. Forty young participants (20M/20F) performed dynamic interactions with 21 different stimuli using their index finger pad at a controlled angle, pressure, and speed. Participants rated their wetness perception using a 100-mm visual analog scale (very dry to very wet). Partial least squares regression analysis indicated that coefficient of friction explained only ∼11% of the variance in wetness perception, whereas Q max and moisture content accounted for ∼22% and 18% of the variance, respectively. These parameters shared positive relationships with wetness perception, such that the greater the Q max, moisture content, and coefficient of friction, the wetter the perception. We found no differences in wetness perception between males and females. Our findings indicate that although the friction of a wet substrate modulates wetness perception, it is still secondary to thermal parameters such as Q max.New and Noteworthy: Our skin often interacts with wet materials, yet how their physical properties influence our experience of wetness remains poorly understood. We evaluated wetness perception following naturalistic haptic interactions with materials varying in moisture content, friction, optical profiles, and heat transfer rates. We show that although mechanical parameters can influence wetness perception, their role is secondary to that of thermal factors. These findings expand our understanding of multisensory integration and could guide innovation in healthcare product design
The visual perception of wetness: the role of stain chroma, size, and hue
No full textA range of sensory cues contribute to human wetness perception, yet we know little of how visual modalities are involved, specifically if in-situ physical observations differ from ex-situ online observations. We aimed to assess the effect of stain volume, chroma, size, and hue on the wetness perception of static images, with a comparison to previously collected in-situ data. A total of 440 participants completed the online study, including 18 from an analogous in-situ study. Stimuli varied in physical wetness (0, 2.16 × 10−4 or 3.45 × 10−4 mL mm−2), stain chroma (clear saline, light synthetic urine, dark synthetic urine) and stain size (1150 or 5000 mm2). Further stimuli of a fixed wetness (3.45 × 10−4 mL mm−2) varied in stain hue (red, orange, yellow, green, blue, violet) and stain size (1150 or 5000 mm2). Participants rated wetness perception using a visual analogue scale (very dry to very wet) and modified yes/no task (dry/wet, gloss/matte, dilute/concentrate). Participants successfully discriminated between all physical wetness levels. Wetness perception shared a positive relationship with stain chroma and size, and varied with hue such that higher wavelengths resulted in greater wetness perception. Finally, online and in-situ wetness perception did not significantly differ.Practical applications: the findings fundamentally contribute to our scientific understanding of wetness perception, giving evidence toward different multisensory integration theories. Further applications lie in industry, such as improving the structure, function, and perception of absorbent hygiene products or informing the design of sportswear with moisture management properties. Additionally, findings may aid the improvement of digital software which uses visual wetness components, for example in augmented and virtual realities
The visual perception of wetness: Multisensory integration of visual and tactile stimuli
No full textA multitude of sensory modalities are involved in humans’ experience of wetness, yet we know little of the integratory role of vision. Therefore, the aim was to quantify the effect of physical stain volume, chroma and size on wetness perception, and to compare wetness perception under different sensory conditions, including visuotactile and visual only interactions. Eighteen participants visually observed and/or used their index fingerpad to dynamically interact with stimuli varying in physical wetness (0, 2.16 × 10
−4 or 3.45 × 10
−4 ml mm
−2), stain chroma (clear, light, dark) and stain size (1150 or 5000 mm
2). After interaction participants rated wetness perception using a visual analogue scale (very dry to very wet). In visual only conditions participants were able to differentiate between dry and wet stimuli, and could also discriminate between different magnitudes of wetness with the addition of tactile cues. In both visual only and visuotactile conditions greater stain chroma resulted in increased wetness perception. Stain size did not have a significant effect in either condition. These results show that visual cues influence wetness perception (R
2 = 0.29), but indicate that visual dominance does not apply in these sensory integrations. Findings are relevant for the design of products with wetness management properties.
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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