348 research outputs found
Settling on leaves or flowers: herbivore feeding site determines the outcome of indirect interactions between herbivores and pollinators
Herbivore attack can alter plant interactions with pollinators, ranging from reduced to enhanced pollinator visitation. The direction and strength of effects of herbivory on pollinator visitation could be contingent on the type of plant tissue or organ attacked by herbivores, but this has seldom been tested experimentally. We investigated the effect of variation in feeding site of herbivorous insects on the visitation by insect pollinators on flowering Brassica nigra plants. We placed herbivores on either leaves or flowers, and recorded the responses of two pollinator species when visiting flowers. Our results show that variation in herbivore feeding site has profound impact on the outcome of herbivore–pollinator interactions. Herbivores feeding on flowers had consistent positive effects on pollinator visitation, whereas herbivores feeding on leaves did not. Herbivores themselves preferred to feed on flowers, and mostly performed best on flowers. We conclude that herbivore feeding site choice can profoundly affect herbivore–pollinator interactions and feeding site thereby makes for an important herbivore trait that can determine the linkage between antagonistic and mutualistic networks.</p
Keith Stirling : An introduction to his life and examination of his music
This study introduces the life and examines the music of Australian jazz trumpeter Keith Stirling (1938-2003). The paper discusses the importance and position of Stirling in the jazz culture of Australian music, introducing key concepts that were influential not only to the development of Australian jazz but also in his life. Subsequently, a discussion of Stirling’s metaphoric tendencies provides an understanding of his philosophical perspectives toward improvisation as an art form. Thereafter, a discourse of the research methodology that was used and the resources that were collected throughout the study introduce a control group of transcriptions. These transcriptions provide an origin of phrases with which to discuss aspects of Stirling’s improvisational style. Instrumental approaches and harmonic concepts are then discussed and exemplified through the analysis of the transcribed phrases. Stirling’s instrumental techniques and harmonic concepts are examined by means of his own and student’s hand written notes and quotes from lesson recordings that took place in the early 1980s
Using computer-aided detection in mammography as a decision support
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87548.pdf (publisher's version ) (Closed access)OBJECTIVE: To evaluate an interactive computer-aided detection (CAD) system for reading mammograms to improve decision making. METHODS: A dedicated mammographic workstation has been developed in which readers can probe image locations for the presence of CAD information. If present, CAD findings are displayed with the computed malignancy rating. A reader study was conducted in which four screening radiologists and five non-radiologists participated to study the effect of this system on detection performance. The participants read 120 cases of which 40 cases had a malignant mass that was missed at the original screening. The readers read each mammogram both with and without CAD in separate sessions. Each reader reported localized findings and assigned a malignancy score per finding. Mean sensitivity was computed in an interval of false-positive fractions less than 10%. RESULTS: Mean sensitivity was 25.1% in the sessions without CAD and 34.8% in the CAD-assisted sessions. The increase in detection performance was significant (p = 0.012). Average reading time was 84.7 +/- 61.5 s/case in the unaided sessions and was not significantly higher when interactive CAD was used (85.9 +/- 57.8 s/case). CONCLUSION: Interactive use of CAD in mammography may be more effective than traditional CAD for improving mass detection without affecting reading time.1 oktober 201
Multimodal discourse on online newspaper home pages: A social-semiotic perspective
In a short space of time, online newspapers have emerged to play an important role in the institutional construction of ‘news’ and the mass mediation of information. The home pages of online newspapers feature short verbal texts, and communicate using language, image, layout, colour, and other semiotic resources: they communicate multimodally. This thesis examines the multimodal discourse of three English-language online newspapers: the Bangkok Post (Thailand), the English-language edition (translated from Chinese) of the People’s Daily (China), and the Sydney Morning Herald (Australia). Between February, 2002 and April, 2006, three data collections were made (February-April, 2002; September-November, 2005; January-April, 2006) using a five-day ‘constructed week’ method. The main corpus was 15 home pages from each newspaper (five per collection per newspaper), but the total corpus (including other pages from each newspaper) was 603 web pages. Two senior editors (one each from the Bangkok Post and the Sydney Morning Herald) were interviewed. The multimodal discourse of the home pages was analysed using tools from Systemic Functional Multimodal Discourse Analysis (SF-MDA), and a ‘visual grammar’ of home pages building on the work of Kress & van Leeuwen (1996) was developed. In addition, a rank scale for online newspapers was proposed, and limitations of applying the tool of rank scale to this corpus were identified. An emerging genre - the headline-plus-lead-plus-hyperlink newsbite - was identified, and the design of newsbites on the home page of the Sydney Morning Herald and the evolution of their design over time was analysed. The use of images on the home pages in the corpus was analysed, and the increasing use of thumbnail images in the Sydney Morning Herald - particularly close-up thumbnails of faces - was investigated in further depth. The visual design of online newspaper home pages and the news texts appearing on them are an evolution of print news genres and their design practices. Newsbites and headline-only newsbits are verbally short, so the authors of newspaper home pages are forced to rely increasingly on visual communication in order to position stories and readers, and to communicate the values of the news institution on the home page as mediated by the screen. Thumbnail images are evolving as a new form of punctuation on some home pages, and this may be a short-lived, or an emerging historical trend in the development of punctuation, at least in online environments. Overall, online newspaper home pages are tending towards shorter texts, which communicate in novel ways. These short texts cannot communicate the values and ideology of news institutions in the way that extended verbal texts have done for centuries, yet this function of news texts remains important to the construction and maintenance of a readership, and therefore crucial to the home page of a newspaper. As a result, news institutions express values visually in their design of newspaper home pages. As readers become familiar with the meanings of online news design, they become adept at reading and understanding short stories within these multimodally-construed frames of reference. Ideology is increasingly fragmented on shorter timescales, but expressed over longer timescales in a hypermedia environment that affords and extends many of the pre-existing multimodal features of print newspaper discourse
The effect of volumetric breast density on the risk of screen-detected and interval breast cancers: a cohort study.
BACKGROUND: In the light of the breast density legislation in the USA, it is important to know a woman's breast cancer risk, but particularly her risk of a tumor that is not detected through mammographic screening (interval cancer). Therefore, we examined the associations of automatically measured volumetric breast density with screen-detected and interval cancer risk, separately. METHODS: Volumetric breast measures were assessed automatically using Volpara version 1.5.0 (Matakina, New Zealand) for the first available digital mammography (DM) examination of 52,814 women (age 50 - 75 years) participating in the Dutch biennial breast cancer screening program between 2003 and 2011. Breast cancer information was obtained from the screening registration system and through linkage with the Netherlands Cancer Registry. We excluded all screen-detected breast cancers diagnosed as a result of the first digital screening examination. During a median follow-up period of 4.2 (IQR 2.0-6.2) years, 523 women were diagnosed with breast cancer of which 299 were screen-detected and 224 were interval breast cancers. The associations between volumetric breast measures and breast cancer risk were determined using Cox proportional hazards analyses. RESULTS: Percentage dense volume was found to be positively associated with both interval and screen-detected breast cancers (hazard ratio (HR) 8.37 (95% CI 4.34-16.17) and HR 1.39 (95% CI 0.82-2.36), respectively, for Volpara density grade category (VDG) 4 compared to VDG1 (p for heterogeneity < 0.001)). Dense volume (DV) was also found to be positively associated with both interval and screen-detected breast cancers (HR 4.92 (95% CI 2.98-8.12) and HR 2.30 (95% CI 1.39-3.80), respectively, for VDG-like category (C)4 compared to C1 (p for heterogeneity = 0.041)). The association between percentage dense volume categories and interval breast cancer risk (HR 8.37) was not significantly stronger than the association between absolute dense volume categories and interval breast cancer risk (HR 4.92). CONCLUSIONS: Our results suggest that both absolute dense volume and percentage dense volume are strong markers of breast cancer risk, but that they are even stronger markers for predicting the occurrence of tumors that are not detected during mammography breast cancer screening
Change in mammographic density across birth cohorts of Dutch breast cancer screening participants
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208976.pdf (publisher's version ) (Open Access
Transfer Learning for Domain Adaptation in MRI: Application in Brain Lesion Segmentation
Magnetic Resonance Imaging (MRI) is widely used in routine clinical diagnosis
and treatment. However, variations in MRI acquisition protocols result in
different appearances of normal and diseased tissue in the images.
Convolutional neural networks (CNNs), which have shown to be successful in many
medical image analysis tasks, are typically sensitive to the variations in
imaging protocols. Therefore, in many cases, networks trained on data acquired
with one MRI protocol, do not perform satisfactorily on data acquired with
different protocols. This limits the use of models trained with large annotated
legacy datasets on a new dataset with a different domain which is often a
recurring situation in clinical settings. In this study, we aim to answer the
following central questions regarding domain adaptation in medical image
analysis: Given a fitted legacy model, 1) How much data from the new domain is
required for a decent adaptation of the original network?; and, 2) What portion
of the pre-trained model parameters should be retrained given a certain number
of the new domain training samples? To address these questions, we conducted
extensive experiments in white matter hyperintensity segmentation task. We
trained a CNN on legacy MR images of brain and evaluated the performance of the
domain-adapted network on the same task with images from a different domain. We
then compared the performance of the model to the surrogate scenarios where
either the same trained network is used or a new network is trained from
scratch on the new dataset.The domain-adapted network tuned only by two
training examples achieved a Dice score of 0.63 substantially outperforming a
similar network trained on the same set of examples from scratch.Comment: 8 pages, 3 figure
The human eye-movement response to maintained surface galvanic vestibular stimulation
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141356.pdf (publisher's version ) (Closed access
Klasifikacija dojki prema gustoći izborom značajki
Mammography as an x-ray method usually gives good results for lower density breasts while higher breast tissue densities significantly reduce the overall detection sensitivity and can lead to false negative results. In automatic detection algorithms knowledge about breast density can be useful for setting an appropriate decision threshold in order to produce more accurate detection. Because the overall intensity of mammograms is not directly correlated with the breast density we have decided to observe breast density as a texture classification problem. In this paper we propose breast density classification using feature selection process for different classifiers based on grayscale features of first and second order. In feature selection process different selection methods were used and obtained results show the improvement on overall classification by choosing the appropriate method and classifier. The classification accuracy has been tested on the mini-MIAS database and KBD-FER digital mammography database with different number of categories for each database. Obtained accuracy stretches between 97.2 % and 76.4 % for different number of categories.Mamografija je rendgenska metoda koja daje dobre rezultate pri slikanju dojki koje imaju manju gustoću, dok joj osjetljivost značajno opada pri snimanju dojki veće gustoće i time može doći do lažno pozitivnih rezultata. Poznavanje gustoće dojke može biti korisno kod algoritama za automatsku detekciju zbog mogućnosti određivanja praga odluke na osnovi tog znanja. S obzirom na to da ukupni intenzitet pojedinog mamograma nije izravno povezan s gustoćom, odlučili smo se promatrati gustoću kao problem klasifikacije teksture. U ovom radu predlažemo klasifikaciju dojki prema gustoći izborom izdvojenih značajki intenziteta prvog i drugog reda za različite klasifikatore. Za određivanje prikladnih značajki koristili smo različite metode i tako dobivene značajke pokazale su bolju točnost klasifikacije za odabrane klasifikatore. Točnost klasifikacije testirali smo na bazi mamografskih slika mini-MIAS i bazi digitalnih mamografskih slika KBD-FER s različitim brojem kategorija u koje su slike bile podijeljene. Postignuta točnost klasifikacije proteže se između 97,2 % i 76,4 % za različit broj kategorija u koje su mamogrami podijeljeni
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