Abstract
Speech interfaces are growing in popularity. Through a review of 99 research papers this work maps the trends, themes, findings and methods of empirical research on speech interfaces in the ...field of human–computer interaction (HCI). We find that studies are usability/theory-focused or explore wider system experiences, evaluating Wizard of Oz, prototypes or developed systems. Measuring task and interaction was common, as was using self-report questionnaires to measure concepts like usability and user attitudes. A thematic analysis of the research found that speech HCI work focuses on nine key topics: system speech production, design insight, modality comparison, experiences with interactive voice response systems, assistive technology and accessibility, user speech production, using speech technology for development, peoples’ experiences with intelligent personal assistants and how user memory affects speech interface interaction. From these insights we identify gaps and challenges in speech research, notably taking into account technological advancements, the need to develop theories of speech interface interaction, grow critical mass in this domain, increase design work and expand research from single to multiple user interaction contexts so as to reflect current use contexts. We also highlight the need to improve measure reliability, validity and consistency, in the wild deployment and reduce barriers to building fully functional speech interfaces for research.
RESEARCH HIGHLIGHTS
Most papers focused on usability/theory-based or wider system experience research with a focus on Wizard of Oz and developed systems
Questionnaires on usability and user attitudes often used but few were reliable or validated
Thematic analysis showed nine primary research topics
Challenges identified in theoretical approaches and design guidelines, engaging with technological advances, multiple user and in the wild contexts, critical research mass and barriers to building speech interfaces
The mechanical properties of the extracellular matrix have an important role in cell growth and differentiation. However, it is unclear as to what extent cancer cells respond to changes in the ...mechanical properties (rigidity/stiffness) of the microenvironment and how this response varies among cancer cell lines.
In this study we used a recently developed 96-well plate system that arrays extracellular matrix-conjugated polyacrylamide gels that increase in stiffness by at least 50-fold across the plate. This plate was used to determine how changes in the rigidity of the extracellular matrix modulate the biological properties of tumor cells. The cell lines tested fall into one of two categories based on their proliferation on substrates of differing stiffness: "rigidity dependent" (those which show an increase in cell growth as extracellular rigidity is increased), and "rigidity independent" (those which grow equally on both soft and stiff substrates). Cells which grew poorly on soft gels also showed decreased spreading and migration under these conditions. More importantly, seeding the cell lines into the lungs of nude mice revealed that the ability of cells to grow on soft gels in vitro correlated with their ability to grow in a soft tissue environment in vivo. The lung carcinoma line A549 responded to culture on soft gels by expressing the differentiated epithelial marker E-cadherin and decreasing the expression of the mesenchymal transcription factor Slug.
These observations suggest that the mechanical properties of the matrix environment play a significant role in regulating the proliferation and the morphological properties of cancer cells. Further, the multiwell format of the soft-plate assay is a useful and effective adjunct to established 3-dimensional cell culture models.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background: The major aim of this study was to investigate whether the motivational salience of food cues (as reflected by their attention-grabbing properties) differs between obese and normal-weight ...subjects in a manner consistent with altered reward system function in obesity. Methodology/Principal Findings: A total of 18 obese and 18 normal-weight, otherwise healthy, adult women between the ages of 18 and 35 participated in an eye-tracking paradigm in combination with a visual probe task. Eye movements and reaction time to food and non-food images were recorded during both fasted and fed conditions in a counterbalanced design. Eating behavior and hunger level were assessed by self-report measures. Obese individuals had higher scores than normal-weight individuals on self-report measures of responsiveness to external food cues and vulnerability to disruptions in control of eating behavior. Both obese and normal-weight individuals demonstrated increased gaze duration for food compared to non-food images in the fasted condition. In the fed condition, however, despite reduced hunger in both groups, obese individuals maintained the increased attention to food images, whereas normal-weight individuals had similar gaze duration for food and non-food images. Additionally, obese individuals had preferential orienting toward food images at the onset of each image. Obese and normal-weight individuals did not differ in reaction time measures in the fasted or fed condition. Conclusions/Significance: Food cue incentive salience is elevated equally in normal-weight and obese individuals during fasting. Obese individuals retain incentive salience for food cues despite feeding and decreased self-report of hunger. Sensitization to food cues in the environment and their dysregulation in obese individuals may play a role in the development and/or maintenance of obesity.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The stereotyped asymmetry of one-cell C. elegans embryos has proven to be an important model for identifying molecular determinants of cell polarity 1. How polarity is initiated is less well ...understood. Polarity establishment depends on centrosomes 2–4, which use two molecularly distinct pathways to break symmetry 5–8. In both, the centrosome's position adjacent to the cell cortex is thought to determine where polarization starts. Defects in centrosome-cortex juxtaposition correlate with defects in polarity establishment in several mutants 4, 9, 10, suggesting that these processes may be linked, but there is no direct test of this. Here we assess how centrosome position relative to the cortex affects polarity establishment. We find that centrosomes can initiate polarity from any position within the embryo volume, but centrosome-cortex proximity decreases the time required to initiate polarity. Polarization itself brings about close centrosome-cortex proximity. Prior to polarization, cytoplasmic microtubules constrain centrosome movement near the cortex, expanding the controversial role of microtubules during polarity establishment 4–6, 11–13. The ability of centrosomes to induce a single polarity axis from any position within the egg emphasizes the flexible, self-organizing properties of polarization in C. elegans embryos and contrasts the common view of C. elegans development as invariant.
► Centrosomes trigger polarity from anywhere in the cell ► Polarity establishment brings about centrosome-cortex proximity ► Cytoplasmic microtubules constrain centrosomes near the cortex
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
CONTEXT Whether epidural analgesia is a better method than parenteral opioids
for postoperative pain control remains controversial. OBJECTIVE To systematically review the efficacy of postoperative ...epidural analgesia
vs parenteral opioids, the primary alternative technique. DATA SOURCES Studies were identified primarily by searching the National Library
of Medicine's PubMed database (1966 to April 25, 2002) and other sources for
studies related to postoperative epidural analgesia. STUDY SELECTION Inclusion criteria were a comparison of epidural therapy vs parenteral
opioids for postoperative analgesia, measurement of pain using a visual analog
scale (VAS) or numeric rating scale, randomization of patients to either therapy,
and adult patients (≥18 years). A total of 1404 abstracts were identified,
100 of which met all inclusion criteria. DATA EXTRACTION Each article was reviewed and data extracted from tables, text, or extrapolated
from figures as needed. Weighted mean pain scores, weighted mean differences
in pain score, and weighted incidences of complications were determined by
using a fixed-effect model. DATA SYNTHESIS Epidural analgesia provided better postoperative analgesia compared
with parenteral opioids (mean SE, 19.40 mm 0.17 vs 29.40 mm 0.20 on
the VAS; P<.001). When analyzed by postoperative
day, epidural analgesia was better than parenteral opioids on each postoperative
day (P<.001 for each day after surgery). For all
types of surgery and pain assessments, all forms of epidural analgesia provided
significantly better postoperative analgesia compared with parenteral opioid
analgesia (P<.001 for all), with the exception
of thoracic epidural analgesia vs opioids for rest pain after thoracic surgery
(weighted mean difference, 0.6 mm; 95% confidence interval, –0.3 to
1.5 mm; P = .12). The complication rates were lower
than expected for nausea or vomiting and pruritus but comparable with existing
data for lower extremity motor block. CONCLUSION Epidural analgesia, regardless of analgesic agent, location of catheter
placement, and type and time of pain assessment, provided better postoperative
analgesia compared with parenteral opioids.
Recombination of photogenerated charge carriers in polymer bulk heterojunction (BHJ) solar cells reduces the short circuit current (Jsc ) and the fill factor (FF). Identifying the mechanism of ...recombination is, therefore, fundamentally important for increasing the power conversion efficiency. Light intensity and temperature-dependent current-voltage measurements on polymer BHJ cells made from a variety of different semiconducting polymers and fullerenes show that the recombination kinetics are voltage dependent and evolve from first-order recombination at short circuit to bimolecular recombination at open circuit as a result of increasing the voltage-dependent charge carrier density in the cell. The “missing 0.3 V” inferred from comparison of the band gaps of the bulk heterojunction materials and the measured open-circuit voltage at room-temperature results from the temperature dependence of the quasi-Fermi levels in the polymer and fullerene domains—a conclusion based on the fundamental statistics of fermions.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The use of molybdenum oxide as the anode interfacial layer in conventional bulk heterojunction polymer solar cells leads to an improved power conversion efficiency and also dramatically increases the ...device stability. This indicates that the engineering of improved anode interface materials is an important method by which to fabricate efficient and stable polymer solar cells.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The increased popularity of CUIs has motivated HCI work around specific approaches to research, design, and implementation, while also reflecting on these topics. However, current research is highly ...fragmented and lacks critical mass around topics such as theory, methods and design. Building this critical mass is a fundamentally multidisciplinary endeavour. CUIs involve language based interaction, either through speech or text, with another agent(s) or device(s). This type of interaction not only needs to engage with traditional HCI approaches, but also to embrace methods from communicative and social sciences. This is crucial for making progress towards human-centred conversational interfaces. Along with the recent ACM SIGCHI Conversational User Interfaces conference (ACM CUI), this special issue showcases research to further solidify the foundations of the field in these areas. Below we outline some key challenges faced by the field, describe the papers in this special issue, and then outline areas for future research.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Small amounts of impurity, even one part in one thousand, in polymer bulk heterojunction solar cells can alter the electronic properties of the device, including reducing the open circuit voltage, ...the short circuit current and the fill factor. Steady state studies show a dramatic increase in the trap‐assisted recombination rate when 6,6‐phenyl C84 butyric acid methyl ester (PC84BM) is introduced as a trap site in polymer bulk heterojunction solar cells made of a blend of the copolymer polyN‐9″‐hepta‐decanyl‐2,7‐carbazole‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole) (PCDTBT) and the fullerene derivative 6,6‐phenyl C61 butyric acid methyl ester (PC60BM). The trap density dependent recombination studied here can be described as a combination of bimolecular and Shockley–Read–Hall recombination; the latter is dramatically enhanced by the addition of the PC84BM traps. This study reveals the importance of impurities in limiting the efficiency of organic solar cell devices and gives insight into the mechanism of the trap‐induced recombination loss.
PC84BM traps provide a definitive measure of trap‐assisted recombination in polymer:fullerene solar cells. The trap‐density‐dependent recombination studied here can be described by the result of bimolecular and Shockley–Read–Hall recombination. Dilute impurities act as an important loss mechanism that may be eliminated via further purification processes. Schematic illustration of the addition of PC84BM in small mass fraction to the polymer bulk‐heterojunction solar cell, showing the chemical structure of PC84BM and PC60BM.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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