Search results for "SSAM"
showing 10 items of 78 documents
The effect of education on migration: evidence from school reform
2010
A polytechnic, higher education reform took place in Finland in the 1990s. It gradually transformed former vocational colleges into polytechnics and expanded higher education to all Finnish regions. We implement instrumental variables estimators that exploit the exogenous variation in the regional availability of polytechnic education together with matriculation exam scores. Our IV results show that polytechnic graduates have a higher migration probability than those of vocational college graduates. However, a master’s degree did not increase migration propensity in comparison with a polytechnic degree. We also find that an increase in the availability of polytechnic education did not reduc…
Crystal Structures and Cytotoxicity of ent-Kaurane-Type Diterpenoids from Two Aspilia Species
2018
A phytochemical investigation of the roots of Aspilia pluriseta led to the isolation of ent-kaurane-type diterpenoids and additional phytochemicals (1⁻23). The structures of the isolated compounds were elucidated based on Nuclear Magnetic Resonance (NMR) spectroscopic and mass spectrometric analyses. The absolute configurations of seven of the ent-kaurane-type diterpenoids (3⁻6, 6b, 7 and 8) were determined by single crystal X-ray diffraction studies. Eleven of the compounds were also isolated from the roots and the aerial parts of Aspilia mossambicensis. The literature NMR assignments for compounds 1 and 5 were revised. In a cytotoxicity assay, 12α-methoxy-ent-kaur-9(11),1…
Successive Invasion-Mediated Interspecific Hybridizations and Population Structure in the Endangered Cichlid Oreochromis mossambicus.
2013
Hybridization between invasive and native species accounts among the major and pernicious threats to biodiversity. The Mozambique tilapia Oreochromis mossambicus, a widely used freshwater aquaculture species, is especially imperiled by this phenomenon since it is recognized by the IUCN as an endangered taxon due to genetic admixture with O. niloticus an invasive congeneric species. The Lower Limpopo and the intermittent Changane River (Mozambique) drain large wetlands of potentially great importance for conservation of O. mossambicus, but their populations have remained unstudied until today. Therefore we aimed (1) to estimate the autochthonous diversity and population structure among genet…
Traccia tematica
2010
Descrizione del problema oggetto dei saggi presenti nella raccolta monografica del n. 3/2010 del Giornale di metafisica. L'intepretazione della metafisica nel concetto di funzione-meta e le sue implicazioni nel dibattito attuale.
Large Depth-of-Field Integral Microscopy by Use of a Liquid Lens
2018
Integral microscopy is a 3D imaging technique that permits the recording of spatial and angular information of microscopic samples. From this information it is possible to calculate a collection of orthographic views with full parallax and to refocus computationally, at will, through the 3D specimen. An important drawback of integral microscopy, especially when dealing with thick samples, is the limited depth of field (DOF) of the perspective views. This imposes a significant limitation on the depth range of computationally refocused images. To overcome this problem, we propose here a new method that is based on the insertion, at the pupil plane of the microscope objective, of an electrical…
What about computational super-resolution in fluorescence Fourier light field microscopy?
2020
Recently, Fourier light field microscopy was proposed to overcome the limitations in conventional light field microscopy by placing a micro-lens array at the aperture stop of the microscope objective instead of the image plane. In this way, a collection of orthographic views from different perspectives are directly captured. When inspecting fluorescent samples, the sensitivity and noise of the sensors are a major concern and large sensor pixels are required to cope with low-light conditions, which implies under-sampling issues. In this context, we analyze the sampling patterns in Fourier light field microscopy to understand to what extent computational super-resolution can be triggered duri…
Fourier-domain lightfield microscopy: a new paradigm in 3D microscopy
2020
Recently, integral (also known as lightfield or plenoptic) imaging concept has been applied successfully to microscopy. The main advantage of lightfield microscopy when compared with conventional 3D imaging techniques is that it offers the possibility of capturing the 3D information of the sample after a single shot. However, integral microscopy is now facing many challenges, like improving the resolution and depth of field of the reconstructed specimens or the development and optimization of specially-adapted reconstruction algorithms. This contribution is devoted to review a new paradigm in lightfield microscopy, namely, the Fourier-domain integral microscope (FiMic), that improves the ca…
Ruolo della mobilità dell’acqua sulla stabilità e la conformazione dei polinucleotidi in microemulsione
2008
Questa memoria mostra i risultati preliminari ottenuti nello studio dell’influenza della mobilità dell’acqua e dell’importanza di questa sul comportamento dei polinucleotidi in sistemi confinati. L’acqua nei sistemi biologici svolge un ruolo determinante sulla stabilità e il polimorfismo del DNA. I tempi di rilassamento protonici, T1 e T2, determinati mediante tecniche NMR a bassa risoluzione, permettono di ottenere informazioni sulla mobilità dell’acqua. Il sistema modello utilizzato per simulare il comportamento dell’acqua endocellulare è la microemulsione ternaria BHDC/benzene/acqua, costituita dal tensioattivo cationico BHDC (cloruro di benzilesadecildimetilammonio) che in assenza di co…
Signal-to-noise ratio in reproducing kernel Hilbert spaces
2018
This paper introduces the kernel signal-to-noise ratio (kSNR) for different machine learning and signal processing applications}. The kSNR seeks to maximize the signal variance while minimizing the estimated noise variance explicitly in a reproducing kernel Hilbert space (rkHs). The kSNR gives rise to considering complex signal-to-noise relations beyond additive noise models, and can be seen as a useful signal-to-noise regularizer for feature extraction and dimensionality reduction. We show that the kSNR generalizes kernel PCA (and other spectral dimensionality reduction methods), least squares SVM, and kernel ridge regression to deal with cases where signal and noise cannot be assumed inde…
Poliaromātisku un polidentātu ligandu sintēze un to izmantošana porainu metālorganisko ietvaru iegūšanai
2018
Poliaromātisku un polidentātu ligandu sintēze un to izmantošana porainu metālorganisko ietvaru iegūšanai. Petkus J., zinātniskais vadītājs Dr. ķīm. Šubins K., konsultēja Dr. h. ķīm. Zicmanis A. Bakalaura darbs, 44 lappuses, 43 attēli, 3 tabulas, 36 literatūras avoti. Latviešu valodā. Bakalaura darbs ir veltīts jaunu heterotriangulēnu atvasinājumu iegūšanas sintēžu uzlabošanai.