| 1. |
- Brydegaard, Mikkel, et al.
(författare)
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On the Exploitation of Mid-infrared Iridescence of Plumage for Remote Classification of Nocturnal Migrating Birds
- 2013
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Ingår i: Applied Spectroscopy. - : SAGE Publications. - 1943-3530 .- 0003-7028. ; 67:5, s. 477-490
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Tidskriftsartikel (refereegranskat)abstract
- A challenging task in ornithology lies in identifying high-altitude nocturnal migrating bird species and genders. While the current approaches including radar, lunar obscuration, and single-band thermal imaging provide means of detection, a more detailed spectral or polarimetric analysis of light has the potential for retrieval of additional information whereby the species and sex could be determined. In this paper, we explore remote classification opportunities provided by iridescent features within feathers in the mid-infrared region. Our approach first involves characterizing the microstructural features of the feather by using rotation and straining, and a scheme for their remote detection is proposed by correlating these microstructural changes to spectral and polarimetric effects. Furthermore, we simulate the spectral signature of the entire bird by using a model that demonstrates how classification would be achieved. Finally, we apply infrared hyperspectral polarization imaging, showing that the net iridescent effect persists for the bird as a whole.
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| 2. |
- Merdasa, Aboma, et al.
(författare)
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Staining-free malaria diagnostics by multispectral and multimodality light-emitting-diode microscopy.
- 2013
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Ingår i: Journal of Biomedical Optics. - 1083-3668. ; 18:3
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Tidskriftsartikel (refereegranskat)abstract
- We report an accurate optical differentiation technique between healthy and malaria-infected erythrocytes by quasi-simultaneous measurements of transmittance, reflectance, and scattering properties of unstained blood smears using a multispectral and multimode light-emitting diode microscope. We propose a technique for automated imaging, identification, and counting of malaria-infected erythrocytes for real-time and cost-effective parasitaemia diagnosis as an effective alternative to the manual screening of stained blood smears, now considered to be the gold standard in malaria diagnosis. We evaluate the performance of our algorithm against manual estimations of an expert and show a spectrally resolved increased scattering from malaria-infected blood cells.
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| 3. |
- Mousavi, Monirehalsadat, et al.
(författare)
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Development of a novel combined fluorescence and reflectance spectroscopy system for guiding high-grade glioma resections _ Confirmation of capability in lab experiments
- 2013
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Ingår i: Biophotonics—Riga 2013 (Proceedings of SPIE). - : SPIE. - 0277-786X .- 1996-756X. ; 9032, s. 90320-90320
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Konferensbidrag (refereegranskat)abstract
- Total resection of glioblastoma multiform (GBM), the most common and aggressive malignant brain tumor, is challenging among other things due to difficulty in intraoperative discrimination between normal and residual tumor cells. This project demonstrates the potential of a system based on a combination of autofluorescence and diffuse reflectance spectroscopy to be useful as an intraoperative guiding tool. In this context, a system based on 5 LEDs coupled to optical fibers was employed to deliver UV/visible light to the sample sequentially. Remitted light from the tissue; including diffuse reflected and fluorescence of endogenous and exogenous fluorophores, as well as its photobleaching product, is transmitted to one photodiode and four avalanche photodiodes. This instrument has been evaluated with very promising results by performing various tissue-equivalent phantom laboratory and clinical studies on skin lesions.
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| 4. |
- Runemark, Anna, et al.
(författare)
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Has the inbreeding load for a condition-dependent sexual signalling trait been purged in insular lizard populations?
- 2013
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083. ; 22:5, s. 1310-1321
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Tidskriftsartikel (refereegranskat)abstract
- Sexually selected traits are often condition-dependent and are expected to be affected by genome-wide distributed deleterious mutations and inbreeding. However, sexual selection is a powerful selective force that can counteract inbreeding through purging of deleterious mutations. Inbreeding and purging of the inbreeding load for sexually selected traits has rarely been studied across natural populations with different degrees of inbreeding. Here we investigate inbreeding effects (measured as marker-based heterozygosity) on condition-dependent sexually selected signalling trait and other morphological traits across islet- and mainland populations (n = 15) of an endemic lizard species (Podarcis gaigeae). Our data suggest inbreeding depression on a condition-dependent sexually selected signalling character among mainland subpopulations with low or intermediate levels of inbreeding, but no sign of inbreeding depression among small and isolated islet populations despite their higher overall inbreeding levels. In contrast, there was no such pattern among ten other morphological traits which are primarily naturally selected and presumably not involved in sexual signalling. These results are in line with purging of recessive deleterious alleles, or purging in combination with stochastic fixation of alleles by genetic drift, for a sexual signalling character in the islet environment, which is characterized by low population sizes and strong sexual selection. Higher clutch sizes in islet populations also raise interesting questions regarding the possibility of antagonistic pleiotropy. Purging and other non-exclusive explanations of our results are discussed.
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| 5. |
- Xie, Zhiyuan, et al.
(författare)
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Novel combined fluorescence/reflectance spectroscopy system for guiding brain tumor resections - hardware considerations
- 2013
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Ingår i: Biophotonics—Riga 2013 (Proceedings of SPIE). - : SPIE. - 0277-786X .- 1996-756X. ; 9032, s. 90320-90320
-
Konferensbidrag (refereegranskat)abstract
- Glioblastoma multiforme (GBM) has long been known as the most common and aggressive form of brain malignancy. The morphological similarities of the malignant and surrounding tissue cause difficulties to distinct the tumors during surgery. In order to achieve better results in resecting malignant brain tumors, a fiber based optical system which can be used intraoperative is developed in this project. In this context, the system hardware details, system controlling interfaces and laboratory testing results are presented. Based on the results obtained from various tests with tissue-equivalent phantoms, the system is proved to have stable performance, robust structure, and have good linearity as well as high sensitivity to low PpIX concentration under strong ambient light conditions.
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