25 research outputs found
Cultural specificity and cinematic narration
Except Indian theories, contemporary theories of cinematic narration seldom sufficiently verify the extent and ends to which cultural specificity informs principles of narration. That predicament is exacerbated by that significant theoretical accounts fail to effectively address the cross-cultural validity of narration theories. This dissertation undertakes to deconstruct these theories, seeking to establish ways in which the structures of cinematic narration and its theorization in specific cultural contexts are continuous with corresponding cultural patterns of thoughts. African, Indian, Latin American and Euro-American theories were therefore selected and analysed for such continuity. The analysis revealed some evidence which suggests the continuity of cinematic narration, and its theorization, with culturally specific patterns of thoughts. Another set of evidence, however, particularly the scarcity of comparative ethnographic studies of cinematic narration and the prevalence of a universalising approach in Euro-American theories, makes this continuity problematic. This dichotomy of evidence highlights issues of cross-cultural validity of narration theories, especially the transposability of theories to different cultural contexts. To be meaningfully addressed, these issues would require consistent ethnographic studies of narration. Such studies would be particularly useful (1) to post-theorist scholars who seek solutions to contextually-motivated theoretical problems, (2) in cross-cultural pluralist film analysis and (3) in studies of national cinema
Optical and mid-infrared line emission in nearby Seyfert galaxies
Line ratio diagnostics provide valuable clues on the source of ionizing
radiation in galaxies with intense black hole accretion and starbursting
events, such as local Seyfert or galaxies at the peak of the star formation
history. We aim to provide a reference joint optical and mid-IR analysis for
studying AGN identification via line ratios and testing predictions from
photoionization models. We obtained homogenous optical spectra with the
Southern Africa Large Telescope for 42 Seyfert galaxies with Spitzer/IRS
spectroscopy and X-ray to mid-IR multiband data available. After confirming the
power of the main optical ([OIII]) and mid-IR ([NeV], [OIV], [NeIII]) emission
lines in tracing AGN activity, we explore diagrams based on ratios of optical
and mid-IR lines by exploiting photoionization models of different ionizing
sources (AGN, star formation and shocks). We find that pure AGN photoionization
models are good at reproducing observations of Seyfert galaxies with an AGN
fractional contribution to the mid-IR (5-40 micron) emission larger than 50 per
cent. For targets with a lower AGN contribution these same models do not fully
reproduce the observed mid-IR line ratios. Mid-IR ratios like [NeV]/[NeII],
[OIV]/[NeII] and [NeIII]/[NeII] show a dependence on the AGN fractional
contribution to the mid-IR unlike optical line ratios. An additional source of
ionization, either from star formation or radiative shocks, can help explain
the observations in the mid-IR. Among combinations of optical and mid-IR
diagnostics in line ratio diagrams, only those involving the [OI]/Halpha ratio
are promising diagnostics for simultaneously unraveling the relative role of
AGN, star formation and, shocks. A proper identification of the dominant
ionizing source would require the exploitation of analysis tools based on
advanced statistical techniques as well as spatially resolved data.Comment: 31 pages, 15 figures, 2 tables. Accepted for publication in A&
Variabilidade genética em populações de pitangueira oriundas de autopolinização e polinização livre, acessada por AFLP
Applying Deep Learning for Breast Cancer Detection in Radiology
Recent advances in deep learning have enhanced medical imaging research. Breast cancer is the most prevalent cancer among women, and many applications have been developed to improve its early detection. The purpose of this review is to examine how various deep learning methods can be applied to breast cancer screening workflows. We summarize deep learning methods, data availability and different screening methods for breast cancer including mammography, thermography, ultrasound and magnetic resonance imaging. In this review, we will explore deep learning in diagnostic breast imaging and describe the literature review. As a conclusion, we discuss some of the limitations and opportunities of integrating artificial intelligence into breast cancer clinical practice
Star formation in far-IR AGN and non-AGN galaxies in the green valley - II. Morphological analysis
This paper studies morphological properties of 103 green valley FIR active and 2609 non-active galaxies presented in Mahoro, Pović & Nkundabakura (2017). The photometric data from the COSMOS survey were used, and the morphological parameters, such as Abraham and Conselice-Bershady concentration indices, Gini, M20 moment of light, and asymmetry, were analysed taking into account public catalogues. Furthermore, a visual classification of galaxies was performed. We found that the fraction of peculiar galaxies with clear signs of interactions and mergers is significantly higher in AGNs (38 per cent) than non-AGN (19 per cent) green valley galaxies, while non-AGN galaxies from our sample are predominantly spirals (46 per cent). We found that the largest fraction of our green valley galaxies is located on the main sequence of star formation, independently on morphology, which is in contrast with most of previous studies carried out in optical. We also found that FIR AGN green valley galaxies have significantly higher star formation rates in all analysed morphological types. Therefore, our results suggest that interactions and mergers obtained in the high fraction of FIR AGNs contribute significantly to high star formation rates observed in the selected sample, but are not the only mechanism responsible for enhancing star formation, and others such as AGN positive feedback could contribute as well. In future we will study in more details the possibility of AGN positive feedback through the spectroscopic analysis of public and our SALT data. © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.This work is based on the research supported in part by the National Research Foundation of South Africa (Grant Numbers 110816). AM acknowledges financial support from the Swedish International Development Cooperation Agency (SIDA) through the International Science Programme (ISP) - Uppsala University to University of Rwanda through the Rwanda Astrophysics, Space and Climate Science Research Group (RASCSRG), East African Astrophysics Research Network (EAARN) are gratefully acknowledged. MP acknowledges financial supports from the Ethiopian Space Science and Technology Institute (ESSTI) under the Ethiopian Ministry of Innovation and Technology (MInT), from the Spanish Ministry of Economy and Competitiveness (MINECO) through projects AYA2013-42227-P and AYA2016-76682C3-1-P, and from the State Agency for Research of the Spanish MCIU through the 'Center of Excellence Severo Ochoa' award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). PV acknowledges support from the National Research Foundation of South Africa.Peer reviewe
PAPER Special Section on Cryptography and Information Security An Extension of GHS Weil Descent Attack ∗
by Gaudry, Hess and Smart (the so-called GHS attack) on elliptic curves over finite fields of characteristic two and with composite extension degrees. Recently, Diem presented a general treatment of the GHS attack to hyperelliptic curves over finite fields of arbitrary odd characteristics. This paper shows that Diem’s approach can be extended to curves of which the function fields are cyclic Galois extensions. In particular, we show the existence of GHS Weil restriction, triviality of the kernel of GHS conorm-norm homomorphism, and lower/upper bounds of genera of the resulting curves. key words: elliptic curves, hyperelliptic curves, superelliptic curves,GHS Weil descent attack, GHS conorm-norm homomorphism, function fields 1
Genetic diversity and population structure of indigenous chicken in Rwanda using microsatellite markers
Rwanda has about 4.5 million of indigenous chicken (IC) that are very low in productivity. To initiate any genetic improvement programme, IC needs to be accurately characterized. The key purpose of this study was to ascertain the genetic diversity of IC in Rwanda using microsatellite markers. Blood samples of IC sampled from 5 agro-ecological zones were collected from which DNA was extracted, amplified by PCR and genotyped using 28 microsatellite markers. A total of 325 (313 indigenous and 12 exotic) chickens were genotyped and revealed a total number of 305 alleles varying between 2 and 22 with a mean of 10.89 per locus. One hundred eighty-six (186) distinct alleles and 60 private alleles were also observed. The frequency of private alleles was highest in samples from the Eastern region, whereas those from the North West had the lowest. The influx of genes was lower in the Eastern agro-ecological zone than the North West. The mean observed heterozygosity was 0.6155, whereas the average expected heterozygosity was 0.688. The overall inbreeding coefficient among the population was 0.040. Divergence from the Hardy-Weinberg equilibrium was significant (p<0.05) in 90% of loci in all the populations. The analysis of molecular variance revealed that about 92% of the total variation originated from variation within populations. Additionally, the study demonstrated that IC in Rwanda could be clustered into four gene groups. In conclusion, there was considerable genetic diversity in IC in Rwanda, which represents a crucial genetic resource that can be conserved or optimized through genetic improvement
Genetic diversity and population structure of indigenous chicken in Rwanda using microsatellite markers
[This corrects the article DOI: 10.1371/journal.pone.0225084.]