54 research outputs found
Mode refinement algorithm for H.264 inter frame requantization
No full textThe latest video coding standard H.264 has been recently approved and has already been adopted for numerous applications including HD-DVD and satellite broadcast. To allow interconnectivity between different applications using H.264, transcoding will be a key factor. When requantizing a bitstream the incoming coding decisions are usually kept unchanged to reduce the complexity, but it can have a major impact on the coding efficiency. This paper proposes a novel algorithm for mode refinement of inter prediction in the case of requantization of H.264 bitstreams. The proposed approach gives a comparable quality to a full search for a fraction of its complexity by exploiting the statistical properties of the mode distribution and motion vector refinementThe latest video coding standard H.264 has been recently approved and has already been adopted for numerous applications including HD-DVD and satellite broadcast. To allow interconnectivity between different applications using H.264, transcoding will be a key factor. When requantizing a bitstream the incoming coding decisions are usually kept unchanged to reduce the complexity, but it can have a major impact on the coding efficiency. This paper proposes a novel algorithm for mode refinement of inter prediction in the case of requantization of H.264 bitstreams. The proposed approach gives a comparable quality to a full search for a fraction of its complexity by exploiting the statistical properties of the mode distribution and motion vector refinemen
Mapping of barley (Hordeum vulgare L.) beta-amylase alleles in which an amino acid substitution determines beta-amylase isoenzyme type and the level of free beta-amylase
No full textThe three beta -amylase genes (Bmy1, 2 and 3) in cultivated barley were mapped to chromosomes 4HL, 2HL And 4HL respectively using RFLP analysis. No recombinants between Bmy1 andBmy3 were detected among 264 DH lines. Polymorphism of the Sd1 and Sd2 isoenzymes of beta -amylase co-segregated with the Bmy loci on chromosome 4HL in a doubled-haploid population of the cross Chebec (Sd2)×Harrington (Sd1). This locus also explained 90·5% of the variation in the level of free enzyme between the two parents. Two cDNAs ofbeta -amylase were isolated by RT-PCR from the developing grains of Harrington (Sd1) and Galleon (Sd2). Alignment of the deduced amino acid sequences identified three amino-acid substitutions between the Sd2 and Sd1 forms of beta -amylase (Arg115 – Cys, Asp165 – Glu, and Val430 – Ala). Three allele-specific PCR primer pairs based on the three amino acid substitutions were used to amplify the beta -amylase genes in genomic DNA of sixteen barley cultivars/lines. Only the Arg115(Sd2)/Cys(Sd1) substitution was consistent with the isoenzyme form. This amino acid replacement reduced the pI of the Sd1 beta -amylase consistent with the fact that the Sd2 form is more basic than the Sd1 form when separated by IEF. The mutation from Arg115 to Cys in the Sd1 form also provides one more -SH group to form S-S-bridges. As bound beta -amylase is linked to the insoluble proteins of the endosperm and its inhibitor via disulphide bridges this could explain the higher level of binding exhibited by Sd1 vs Sd2. Thus a single amino acid substitution determines both the isoenzyme type and beta -amylase binding.Li, C.-D. ; Langridge, P. ; Zhang, X.-Q. ; Eckstein, P.E. ; Rossnagel, B.G. ; Lance, R.C.M. ; Lefol, E.B. ; Lu, M.-Y. ; Harvey, B.L. ; Scoles, G.J
Theory and Practice of Government : abū Ḥammū Mūsā l-Zayyānī’s (d. 791/1389) Mirror for Princes : critical Edition and Analysis of Wāsiṭat al-sulūk fī siyāsat al-mulūk
No full textLe Wāsiṭat al-sulūk fī siyāsat al-mulūk est un miroir des princes rédigé au VIIIe/XIVe siècle par le souverain zayyānide de Tlemcen, Abū Ḥammū Mūsā II (m. 791/1389). À l’instar de nombreux miroirs des princes tardifs composés au Maghreb, cet ouvrage n’a pas suscité l’intérêt de nombreux chercheurs et aucune étude approfondie ne lui a été consacrée. Ce travail de recherche propose donc d’en établir une édition critique et d’en faire l’analyse. Il s’agit de s’interroger sur les spécificités de ce miroir des princes, d’une part, en analysant le discours théorique sur le bon gouvernement à la lumière du contexte particulier dans lequel ce livre a été rédigé et en le confrontant à l’expérience politique propre à son auteur et, d’autre part, en le comparant aux ouvrages qui en constituent les principales sources. Cette étude vise également à analyser la terminologie employée dans le Wāsiṭat al-sulūk fī siyāsat al-mulūk afin de mieux appréhender certains concepts fréquemment employés dans les miroirs des princes, tels ceux de siyāsa, de tadbīr, de ḥazm ou encore de ẖāṣṣa, et de déterminer l’emploi particulier qui en est fait dans l’ouvrage. Enfin, le récit des événements dans lequel l’auteur se met lui-même en scène est analysé et comparé au récit des mêmes événements relayé par ses contemporains afin de mettre en lumière les stratégies d’écriture mises en œuvre dans l’ouvrage et d’établir les différentes fonctions de ce miroir des princes qui ne peut se réduire à une simple compilation de conseils destinés au prince héritier.Wāsiṭat al-sulūk fī siyāsat al-mulūk is a Mirror for Princes written in the 8th/14th century by the Zayyānid ruler of Tlemcen, Abū Ḥammū Mūsā II (d. 791/1389). Similarly to many later Mirrors for Princes composed in the Maghreb, this book did not attract the interest of many researchers and no comprehensive study was made of it. This research work proposes to establish a critical edition of it and to analyze it. The aim is to consider the specificities of this Mirror for Princes, on the one hand, by analyzing the theoretical discourse on good government in the light of the particular context in which this book was written and by comparing it with the political experience of its author and, on the other hand, by comparing it with the works constituting its principal sources. This study also aims to analyze the terminology used in the Wāsiṭat al-sulūk fī siyāsat al-mulūk to better understand certain concepts frequently used in the Mirrors for Princes, such as those of siyāsa, tadbīr, ḥazm and ẖāṣṣa, and to determine the particular use that is made of them in the work. Finally, the narrative of events which the author himself develops as one of the protagonists is analyzed and compared to the story of the same events relayed by his contemporaries in order to highlight the writing strategies implemented in the book and to establish the different functions of this Mirror for Princes which is far more than a simple compilation of advice intended for the Crown Prince
Caracterização energética do cavaco de eucalyptusgrandis “in natura” e torrefeito
No full textA biomassa vem sendo estudada como uma alternativa de fonte de energia que provoca
um menor impacto ambiental, para produção de biocombustíveis. Entretanto, a biomassa
apresenta algumas desvantagens, tais como o alto teor de umidade, natureza higroscópica,
baixa densidade energética, difícil armazenagem que, consequentemente, inviabiliza a
logística e seu uso direto como combustível. Uma maneira de atenuar essas desvantagens é
através do processo de torrefação, o qual converte a biomassa em um biocombustível sólido
de alto potencial energético. A torrefação é um processo de conversão termoquímica que
ocorre na fase endotérmica da pirólise, e tem como objetivo concentrar a energia da biomassa
em curto tempo e obter altos rendimentos. O presente trabalho teve como objetivo caracterizar
energeticamente as amostras de cavaco in natura e torrefeita para avaliar a influência os
benefícios do processo de torrefação nas propriedades da madeira de Eucalyptus grandis para
que seja usada como combustível. As amostras in natura e previamente torrefeitas (250, 290 e
310 °C) foram caracterizadas para comparação dos resultados. As amostras foram
caracterizadas por análises físico-químicas: análise elementar (C, H, N, O), análise imediata
(umidade, voláteis, cinza e carbono fixo) e poder calorífico (PCS e PCI). A determinação da
faixa de decomposição da hemicelulose, celulose e lignina foi obtida por análise
termogravimétrica (TGA) realizadas com N2. De acordo com os resultados, verificou-se que o
processo de torrefação melhorou de forma significativa as propriedades energéticas da
biomassa estudada. O poder calorífico superior teve um acréscimo em torno de 25 %; o teor
de carbono fixo e de cinzas também aumentou 60 % e 0,6 %, respectivamente. Devido à
decomposição em grande parte da hemicelulose, a umidade (70 %) e os materiais volátil (60
%) reduziram. A partir da análise elementar observou-se um aumento no teor de carbono e
uma redução na razão O/C, o que indica uma maior quantidade de energia retida no
biocombustível. Através do TGA foi observada a influência da temperatura de torrefação na
redução de massa das amostras. Uma grande perda de massa ocorreu entre 210 e 450 °C, que
representa a decomposição da hemicelulose. A amostra in natura e torrefeita a 250 °C foram
as que tiveram maior perda de massa. Desta forma pode-se verificar, de acordo com os
resultados obtidos, que o processo de torrefação é um procedimento viável para o
condicionamento de energia de biomassa de eucalipto. Esse tramamento provoca mudanças
significativas nas propriedades e benefícios para o seu transporte. Com a logística viabilizada
e as mudanças favoráveis das propriedades da biomassa torrefeita, esta possui diferentes
finalidades para sua aplicação na geração de energia térmica e ou elétric
Evaluating the Ecological Impacts of Cultivating Genetically Modified Herbicide Tolerant (GMHT) Oilseed Rape and Maize: (2007-B-DS-1-S1) STRIVE Report
No full textThis report is published as part of the Science, Technology, Research and Innovation for the
Environment (STRIVE) Programme 2007–2013.Author has checked copyrigh
The microbiota associated to grape yellows leafhopper vectors: which potential for symbiotic control?
No full textEurope is the main wine-producing area in the world. Flavescence
Dorée (FD), an insect-borne grape yellow disease, is
causing economic losses from Portugal to Hungary and is a
major cause of concern, among others, in wine production areas
in north Spain, south France and north Italy (Angelini et al.,
2001, Vitis 40:79–86). Cell wall less bacteria, previously termed
mycoplasma-like organisms, and re-named as ‘Candidatus Phytoplasma
vitis’, are the causative agents of FD in grapevine
(Lefol et al., 1994, J. Invertebr. Pathol. 63:285–293). FD is transmitted
by a leafhopper widespread in vineyards, Scaphoideus
titanus (Hemiptera: Cicadellidae), which inoculates the phytoplasma
into the phloem of healthy plants while feeding on the
lymph. FD control is a high priority in European wine producing
areas and is currently achieved through the destruction of
infected vineyards and by extensive insecticide treatments
against S. titanus, while direct control strategies are not yet available.
The actual control strategy by chemical treatments has
obvious economical and ecological impacts, and insecticide
treatments are incompatible with organic production. In recent
years there has been an increasing interest in the potential use of
biological control microorganisms, which are pathogenic to
insect. However this technology, when available, require spraying
of the biocontrol agent at each growing season, with consequent
economic charge and risk of resistance development
Early detection of non-visible sprouting in barley seed using rapid viscosity analysis
No full text Export of grain for malting markets requires viable seed that can withstand storage and shipping conditions. Malting barley is selected for rapid germination. However, barley from the Canadian prairies has minimal dormancy, leading to high risk of sprouting. The goal of this study was to assess the suitability of rapid viscosity analysis (RVA) to detect early non-visible sprouting. Cultivars Harrington (for North America), Alexis (Europe) and CDC Dolly (Western Canada feed barley with low alpha-amylase enzyme activity) were greenhouse grown in Saskatoon, Saskatchewan, and treated in a growth chamber at 12 combinations of t emperature (5 to 22°C) and relative humidity (RH; 60 to 95%) for 1 to 9 d at each of two growth stages, physiological or harvest maturity. Harvested seed from treated plants was measured by RVA, alpha-amylase activity, and germination tests. High RVA final viscosity values (> 150) indicated zero sprouting; RVA < 100 and alpha-amylase values > 125 nmol CU h-1 were associated with sprouting. Alexis sprouted more readily than Harrington and CDC Dolly. More than 3 d at 7.5 to 10°C and > 70% RH induced sprouting at harvest maturity. Future research is needed to further refine the RVA cut-off value on a cultivar basis for identifying problem seed. However, in the meantime, these findings can be used by breeding programs to screen genotypes for improved dormancy and by industry to detect barley viability problems prior to storage or transit. Key words: Rapid viscosity, germination, vigor, sprouting, alpha-amylase, barley </jats:p
Simulating evolutionary responses of an introgressed insect resistance trait for ecological effect assessment of transgene flow: a model for supporting informed decisionmaking in environmental risk assessment
No full textPredicting outcomes of transgene flow from arable crops requires a system perspective that considers ecological and evolutionary processes within a landscape context. In Europe, the arable weed Raphanus raphanistrum is a potential hybridization partner of oilseed rape, and the two species are ecologically linked through the common herbivores Meligethes spp. Observations in Switzerland show that high densities of Meligethes beetles maintained by oilseed rape crops can lead to considerable damage on R. raphanistrum. We asked how increased insect resistance in R. raphanistrum – as might be acquired through introgression from transgenic oilseed rape – would affect seed production under natural herbivore pressure. In simulation experiments, plants protected against Meligethes beetles produced about twice as many seeds as unprotected plants. All stages in the development of reproductive structures from buds to pods were negatively affected by the herbivore, with the transition from buds to flowers being the most vulnerable. We conclude that resistance to Meligethes beetles could confer a considerable selective advantage upon R. raphanistrum in regions where oilseed rape is widely grown
Química Sem Fronteiras: o desafio da energia
No full textCoal, natural gas and petroleum-based liquid fuels are still the most widely used energy sources in modern society. The current scenario contrasts with the foreseen shortage of petroleum that was spread out in the beginning of the XXI century, when the concept of "energy security" emerged as an urgent agenda to ensure a good balance between energy supply and demand. Much beyond protecting refineries and oil ducts from terrorist attacks, these issues soon developed to a portfolio of measures related to process sustainability, involving at least three fundamental dimensions: (a) the need for technological breakthroughs to improve energy production worldwide; (b) the improvement of energy efficiency in all sectors of modern society; and (c) the increase of the social perception that education is a key-word towards a better use of our energy resources. Together with these technological, economic or social issues, "energy security" is also strongly influenced by environmental issues involving greenhouse gas emissions, loss of biodiversity in environmentally sensitive areas, pollution and poor solid waste management. For these and other reasons, the implementation of more sustainable practices in our currently available industrial facilities and the search for alternative energy sources that could partly replace the fossil fuels became a major priority throughout the world. Regarding fossil fuels, the main technological bottlenecks are related to the exploitation of less accessible petroleum resources such as those in the pre-salt layer, ranging from the proper characterization of these deep-water oil reservoirs, the development of lighter and more efficient equipment for both exploration and exploitation, the optimization of the drilling techniques, the achievement of further improvements in production yields and the establishment of specialized training programs for the technical staff. The production of natural gas from shale is also emerging in several countries but its production in large scale has several problems ranging from the unavoidable environmental impact of shale mining as well as to the bad consequences of its large scale exploitation in the past. The large scale use of coal has similar environmental problems, which are aggravated by difficulties in its proper characterization. Also, the mitigation of harmful gases and particulate matter that are released as a result of combustion is still depending on the development of new gas cleaning technologies including more efficient catalysts to improve its emission profile. On the other hand, biofuels are still struggling to fulfill their role in reducing our high dependence on fossil fuels. Fatty acid alkyl esters (biodiesel) from vegetable oils and ethanol from cane sucrose and corn starch are mature technologies whose market share is partially limited by the availability of their raw materials. For this reason, there has been a great effort to develop "second-generation" technologies to produce methanol, ethanol, butanol, biodiesel, biogas (methane), bio-oils, syngas and synthetic fuels from lower grade renewable feedstocks such as lignocellulosic materials whose consumption would not interfere with the rather sensitive issues of food security. Advanced fermentation processes are envisaged as "third generation" technologies and these are primarily linked to the use of algae feedstocks as well as other organisms that could produce biofuels or simply provide microbial biomass for the processes listed above. Due to the complexity and cost of their production chain, "third generation" technologies usually aim at high value added biofuels such as biojet fuel, biohydrogen and hydrocarbons with a fuel performance similar to diesel or gasoline, situations in which the use of genetically modified organisms is usually required. In general, the main challenges in this field could be summarized as follows: (a) the need for prospecting alternative sources of biomass that are not linked to the food chain; (b) the intensive use of green chemistry principles in our current industrial activities; (c) the development of mature technologies for the production of second and third generation biofuels; (d) the development of safe bioprocesses that are based on environmentally benign microorganisms; (e) the scale-up of potential technologies to a suitable demonstration scale; and (f) the full understanding of the technological and environmental implications of the food vs. fuel debate. On the basis of these, the main objective of this article is to stimulate the discussion and help the decision making regarding "energy security" issues and their challenges for modern society, in such a way to encourage the participation of the Brazilian Chemistry community in the design of a road map for a safer, sustainable and prosper future for our nation
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