Browsing by Subject "Image analysis"

Sort by: Order: Results:

Now showing items 1-7 of 7
  • Apu, Ehsanul Hoque; Akram, Saad Ullah; Rissanen, Jouni; Wan, Hong; Salo, Tuula (2018)
    Desmoglein 3 (Dsg3) is an adhesion receptor in desmosomes, but its role in carcinoma cell migration and invasion is mostly unknown. Our aim was to quantitatively analyse the motion of Dsg3-modified carcinoma cells in 2D settings and in 3D within tumour microenvironment mimicking (TMEM) matrices. We tested mutant constructs of C-terminally truncated Dsg3 (Delta 238 and Delta 560), overexpressed full-length (FL) Dsg3, and empty vector control (Ct) of buccal mucosa squamous cell carcinoma (SqCC/Y1) cells. We captured live cell images and analysed migration velocities and accumulated and Euclidean distances. We compared rodent collagen and Matrigel. with human Myogel TMEM matrices for these parameters in 3D sandwich, in which we also tested the effects of monoclonal antibody AK23, which targets the EC1 domain of Dsg3. In monolayer culture, FL and both truncated constructs migrated faster and had higher accumulated distances than Ct cells. However, in the 3D assays, only the mutants invaded faster relative to Ct cells. Of the mutants, the shorter form (Delta 238) exhibited faster migration and invasion than Delta 560 cells. In the Transwell, all of the cells invaded faster through Myogel than Matrigel coated wells. In 3D sandwich, AK23 antibody inhibited only the invasion of FL cells. We conclude that different experimental 2D and 3D settings can markedly influence the movement of oral carcinoma cells with various Dsg3 modifications.
  • Blanco, David; Antikainen, Osmo; Räikkönen, Heikki; Yliruusi, Jouko; Juppo, Anne Mari (2021)
    The effect of colloidal silicon dioxide (CSD) on powder flow properties of poor-flowing excipient lactose 200 M was investigated. Binary mixtures of different ratios of CSD as glidant were examined using a modern imagebased flow measuring technique. Special attention was placed to subtle variations in powder flow from small changes in glidant concentration (0.025% w/w). Understanding the modes of interaction of particles and their effects on flowability using the method predicted the die filling performance during tablet manufacture. In addition, the importance of moisture content on powder flow properties was empirically underlined. A more efficient range of CSD was detected from 0.10 to 0.50% w/w in most of the tested conditions, which revealed a significant improvement in powder flow performance compared to higher amounts typically handled in the pharmaceutical industry.
  • Raatevaara, Antti; Korpunen, Heikki; Tiitta, Markku; Tomppo, Laura; Kulju, Sampo; Antikainen, Jukka; Uusitalo, Jori (2020)
    Scots pine (Pinus sylvestris L.) heartwood is naturally durable wood material which has not been fully utilized in the wood industry. Currently, there are no practical measurement methods for detecting and measuring heartwood in a tree harvesting. The objective of this study was to evaluate the applicability of an electrical impedance spectroscopy and an image analysis of a log end face for pine heartwood measurements from the harvesting perspective. Both methods were tested with a fresh wood material which was collected during the harvesting operations. The results indicate that both methods have potential to measure the heartwood from processed stems with an average heartwood diameter error being less than two centimeters for each method. However, the image analysis of the log end face is only appropriate when visible contrast between the heartwood and a sapwood exists. Our findings indicate that the studied heartwood detection methods show great potential in measuring the heartwood of the stem in the harvesting phase which would ideally benefit later links in wood value chains.
  • Kärhä, Kalle; Nurmela, Sari; Karvonen, Heikki; Kivinen, Veli-Pekka; Melkas, Timo; Nieminen, Miikka (2019)
    Trestima Stack is a mobile application innovated by Trestima Ltd. It is based on machine vision, which measures the volume of a timber stack from images taken by a smartphone or a tablet device. The aim of this study was to determine the accuracy (i.e. measurement difference) and effective measurement time consumption of the Trestima Stack application compared to a conventional stacked timber measurement method. Research data consisted of a total of 60 timber stacks, of which 32 were measured in terminal and intermediate yards and 28 at roadside landings. The control volumes of the stacks were measured in September 2016 - January 2017 at the Stora Enso Anjala, Imatra and Varkaus mills by hydrostatic weighting. The total control volume of pulpwood in the study was 11,957 m(3) solid over the bark (m(3)). Across all study data, the accuracy of Trestima Stack averaged + 2.7%. In large terminal yards, accuracy was better (+ 0.7%) than at smaller roadside landings (+ 4.5%), whereas with the conventional stacked timber measurement method, the measurement accuracy was at a similar level in terminal yards (- 4.8%) as at roadside landings (- 4.9%). There was a statistically significant difference between the measurement methods used in measurement accuracy. The most common reason for inaccuracy with the Trestima Stack application was empty space in the final image framing around the stack. The average effective total measurement time consumption with Trestima Stack was 10.6 s/m(3), while it was 13.7 s/m(3) with the conventional stacked timber measurement method. For both measurement methods, there was a statistically significant negative correlation between the stack size and the volume-based effective total measurement time consumption. On the basis of this study, the Trestima Stack application can be recommended for inventorying timber stacks at the roadside landings, particularly when the stacks measured consist of several measurement batches.
  • Blanco, David; Antikainen, Osmo; Räikkönen, Heikki; Pei Ting Mah; Healy, Anne Marie; Juppo, Anne Mari; Yliruusi, Jouko (2020)
    Powder flowability plays an important role in die filling during tablet manufacturing. The present study introduces a novel small-scale measuring technique for powder flow. Based on image analysis, the flow was defined depending on the variation of luminous intensity and the movement of powder inside the measurement cuvette. Using quantities around 100 mg it was possible to characterize a wide range of common pharmaceutical powders, especially in distinguishing subtle differences in flow caused by minor changes in samples characteristics. The method was compared with powder rheometry, which is widely used in the pharmaceutical literature, and showed a significant improvement in predicting the success of pharmaceutical minitablet manufacture (d = 5 mm). Tablet weight variation (RSD) was defined as the most efficient way to assess relevant powder flow behaviour in tablet production when using the novel device. The proposed method was distinguished from others by its ability to classify different grades of microcrystalline cellulose in the die-filling process. Subsequently, eight common pharmaceutical powders, both excipients and APIs, were properly ranked as a function of flowability based on their physical properties. The method showed a high repeatability, with a relative standard deviation not more than 10%.
  • Wang, Aimei; Islam, Md Nahidul; Johansen, Anders; Haapalainen, Minna; Latvala, Satu; Edelenbos, Merete (2019)
    Diseases develop during the storage of onions. To minimize losses, new methods are needed to identify diseased bulbs early in storage. Volatile organic compounds (VOCs), the respiration rate, weight loss, and the dry matter content were investigated for 1-7 weeks post inoculation of bulbs with water (control) and two strains (Fox006 or Fox260) of Fusarium oxysporum f. sp. cepae. Photos, multispectral image analysis, and real-time polymerase chain reaction (PCR) showed no infection in the control onions, weak pathogenic infection in Fox006-onions, and strong pathogenic infection in Fox260-onions at week 7 post inoculation. Infected bulbs exhibited increased respiration rate, increased VOC emission rate, and increased weight loss. The control and Fox006-onions did not respond to inoculation and had similar reaction pattern. Forty-three different VOCs were measured, of which 17 compounds had sulfur in their chemical structure. 1-Propanethiol, methyl propyl sulfide, and styrene were emitted in high concentrations and were positively correlated with the extent of infection (r = 0.82 - 0.89). Therefore, these compounds were the most promising volatile markers of Fusarium basal rot infection. For the first time, we show that the extent of fungal infection determined by real-time PCR in onion bulbs is related with VOC emission.
  • Punkari, Kerttuli (Helsingin yliopisto, 2022)
    Objectives. Recently, an increasing number of comprehensive schools in Helsinki have launched social media accounts, which they use to share visual images during the school days. The purpose of this study is to describe and analyse the ways in which schools portray themselves on the photo-sharing site Instagram, and how these visualisations represent the narratives of the Finnish comprehensive school and the National Core Curriculum for Basic Education. This analysis of Instagram images complements the research on the Finnish comprehensive school system, providing a new and authentic perspective on how schools wish to represent themselves through social media. Methods. This qualitative research is based on a data-driven visual content analysis. The material consists of 766 media images published on the Instagram accounts of seven comprehensive schools in the City of Helsinki during the three-month period between January and March 2021. The visual media were analysed using image analysis and thematic analysis. Results and Conclusions. The results of the analysis indicate that at the time of data analysis the visualisations by selected comprehensive schools in Helsinki are highly diverse. A series of images (Instagram carousel post) is the most common kind of post (83%). In half of the images (50%) there are no people. Of images containing people, groups of students (22%) are presented more often than individuals (5%). As a rule, the people in the images cannot be identified. The classroom (51%) is the most photographed learning place, and the next most frequent image location is outdoors (17%). Furthermore, five main themes emerge from analysis of the images: Steps of Learning (34%), Exhibition (24%), Our School (17%), Outdoor Activities (17%), and Current Topics (8%). The learning process, especially in arts, crafts, and home economics, is displayed in the images, as are the students’ learning outcomes.