171 research outputs found
Making silicon hydrophobic: wettability control by two-lengthscale simultaneous patterning with femtosecond laser irradiation
We report on the wettability properties of silicon surfaces, simultaneously structured on the
micrometre-scale and the nanometre-scale by femtosecond (fs) laser irradiation to render
silicon hydrophobic. By varying the laser fluence, it was possible to control the wetting
properties of a silicon surface through a systematic and reproducible variation of the
surface roughness. In particular, the siliconâwater contact angle could be increased from
66° to more
than 130°. Such behaviour is described by incomplete liquid penetration within the silicon features,
still leaving partially trapped air inside. We also show how controllable design and
tailoring of the surface microstructures by wettability gradients can drive the
motion of the drop's centre of mass towards a desired direction (even upwards)
Informedia at TRECVID 2003: Analyzing and searching broadcast news video
We submitted a number of semantic classifiers, most of which were merely trained on keyframes. We also experimented with runs of classifiers were trained exclusively on text data and relative time within the video, while a few were trained using all available multiple modalities. 1.2 Interactive search This year, we submitted two runs using different versions of the Informedia systems. In one run, a version identical to last year's interactive system was used by five researchers, who split up the topics between themselves. The system interface emphasizes text queries, allowing search across ASR, closed captions and OCR text. The result set can then be manipulated through: ⢠storyboards of images spanning across video story segments ⢠emphasizing matching shots to a userâs query to reduce the image count to a manageable size ⢠resolution and layout under user control ⢠additional filtering provided through shot classifiers such as outdoors, and shots with people, etc. ⢠display of filter count and distribution to guide their use in manipulating storyboard views. In the best-performing interactive run, for all topics a single researcher used an improved version of the system, which allowed more effective browsing and visualization of the results of text queries using
Natural occurrence of Cucumber mosaic virus infecting water mint (Mentha aquatica) in Antalya and Konya, Turkey
A virus causing a disease in mint (the aromatic and culinary plant) has recently become a problem in the Taurus Mountains, a mountain range in the Mediterranean region of Turkey. To detect the virus and investigate its distribution in the region, mint leaf samples were collected from the vicinity of spring areas in the plateaus of Antalya and Konya in 2009. It was found that Cucumber mosaic virus (CMV) was detected in 27.08% of symptomatic samples tested by DAS-ELISA. To the best of our knowledge, this is the first report of CMV on mint plants in this region of Turkey
A music context for teaching introductory computing
We describe myro.chuck, a Python module for controlling music synthesis, and its applications to teaching introductory computer science. The module was built within the Myro framework using the ChucK programming language, and was used in an introductory computer science course combining robots, graphics and music. The results supported the value of music in engaging students and broadening their view of computer science
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A computational study on outliers in world music
The comparative analysis of world music cultures has been the focus of several ethnomusicological studies in the last century. With the advances of Music Information Retrieval and the increased accessibility of sound archives, large-scale analysis of world music with computational tools is today feasible. We investigate music similarity in a corpus of 8200 recordings of folk and traditional music from 137 countries around the world. In particular, we aim to identify music recordings that are most distinct compared to the rest of our corpus. We refer to these recordings as âoutliersâ. We use signal processing tools to extract music information from audio recordings, data mining to quantify similarity and detect outliers, and spatial statistics to account for geographical correlation. Our findings suggest that Botswana is the country with the most distinct recordings in the corpus and China is the country with the most distinct recordings when considering spatial correlation. Our analysis includes a comparison of musical attributes and styles that contribute to the âuniquenessâ of the music of each country
Cumulants and the moment algebra: tools for analysing weak measurements
Recently it has been shown that cumulants significantly simplify the analysis
of multipartite weak measurements. Here we consider the mathematical structure
that underlies this, and find that it can be formulated in terms of what we
call the moment algebra. Apart from resulting in simpler proofs, the
flexibility of this structure allows generalizations of the original results to
a number of weak measurement scenarios, including one where the weakly
interacting pointers reach thermal equilibrium with the probed system.Comment: Journal reference added, minor correction
Fetal lung underdevelopment is rescued by administration of amniotic fluid stem cell extracellular vesicles in rodents
Fetal lung underdevelopment, also known as pulmonary hypoplasia, is characterized by decreased lung growth and maturation. The most common birth defect found in babies with pulmonary hypoplasia is congenital diaphragmatic hernia (CDH). Despite research and clinical advances, babies with CDH still have high morbidity and mortality rates, which are directly related to the severity of lung underdevelopment. To date, there is no effective treatment that promotes fetal lung growth and maturation. Here, we describe a stem cellâbased approach in rodents that enhances fetal lung development via the administration of extracellular vesicles (EVs) derived from amniotic fluid stem cells (AFSCs). Using fetal rodent models of pulmonary hypoplasia (primary epithelial cells, organoids, explants, and in vivo), we demonstrated that AFSC-EV administration promoted branching morphogenesis and alveolarization, rescued tissue homeostasis, and stimulated epithelial cell and fibroblast differentiation. We confirmed this regenerative ability in in vitro models of lung injury using human material, where human AFSC-EVs obtained following good manufacturing practices restored pulmonary epithelial homeostasis. Investigating EV mechanism of action, we found that AFSC-EV beneficial effects were exerted via the release of RNA cargo. MicroRNAs regulating the expression of genes involved in lung development, such as the miR17â92 cluster and its paralogs, were highly enriched in AFSC-EVs and were increased in AFSC-EVâtreated primary lung epithelial cells compared to untreated cells. Our findings suggest that AFSC-EVs hold regenerative ability for underdeveloped fetal lungs, demonstrating potential for therapeutic application in patients with pulmonary hypoplasia
Summary statistics in auditory perception
Sensory signals are transduced at high resolution, but their structure must be stored in a more compact format. Here we provide evidence that the auditory system summarizes the temporal details of sounds using time-averaged statistics. We measured discrimination of 'sound textures' that were characterized by particular statistical properties, as normally result from the superposition of many acoustic features in auditory scenes. When listeners discriminated examples of different textures, performance improved with excerpt duration. In contrast, when listeners discriminated different examples of the same texture, performance declined with duration, a paradoxical result given that the information available for discrimination grows with duration. These results indicate that once these sounds are of moderate length, the brain's representation is limited to time-averaged statistics, which, for different examples of the same texture, converge to the same values with increasing duration. Such statistical representations produce good categorical discrimination, but limit the ability to discern temporal detail.Howard Hughes Medical Institut
Antimicrobial activity of ProRoot MTA in contact with blood
Dental materials based on Portland cement, which is used in the construction industry have gained popularity for clinical use due to their hydraulic properties, the interaction with tooth tissue and their antimicrobial properties. The antimicrobial properties are optimal in vitro. However in clinical use contact with blood may affect the antimicrobial properties. This study aims to assess whether antimicrobial properties of the Portland cement-based dental cements such as mineral trioxide aggregate (MTA) are also affected by contact with blood present in clinical situations. ProRoot MTA, a Portland cement-based dental cement was characterized following contact with water, or heparinized blood after 1âday and 7 days aging. The antimicrobial activity under the mentioned conditions was assessed using 3 antimicrobial tests: agar diffusion test, direct contact test and intratubular infection test. MTA in contact with blood was severely discoloured, exhibited an additional phosphorus peak in elemental analysis, no calcium hydroxide peaks and no areas of bacterial inhibition growth in the agar diffusion test were demonstrated. ProRoot MTA showed limited antimicrobial activity, in both the direct contact test and intratubular infection test. When aged in water ProRoot MTA showed higher antimicrobial activity than when aged in blood. Antimicrobial activity reduced significantly after 7 days. Further assessment is required to investigate behaviour in clinical situations.ERDF (Malta) for the financing of the testing equipment through the project: âDeveloping an Interdisciplinary Material Testing and Rapid Prototyping R&D Facilityâ (Ref. no. 012)
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