178 research outputs found
A pixel-based complexity model to estimate energy consumption in video decoders
The increasing use of HEVC video streams in diverse multimedia applications is driving the need for higher user control and management of energy consumption in battery-powered devices. This paper presents a contribution for the lack of adequate solutions by proposing a pixel-based complexity model that is capable of estimating the energy consumption of an arbitrary software-based HEVC decoder, running on different hardware platforms and devices. In the proposed model, the computational complexity is defined as a linear function of the number of pixels processed by the main decoding functions, using weighting coefficients which represent the average computational effort that each decoding function requires per pixel.
The results shows that the cross-correlation of frame-based complexity estimation with energy consumption is greater than 0.86. The energy consumption of video decoding is estimated with the proposed model within an average deviation range of about 6.9%, for different test sequences.info:eu-repo/semantics/publishedVersio
HRGC-MS analysis of terpenoids from Maytenus ilicifolia and Maytenus aquifolium ("espinheira santa")
Social network analytics and visualization: Dynamic topic-based influence analysis in evolving micro-blogs
Influence Analysis is one of the well-known areas of Social Network Analysis. However, discovering influencers from micro-blog networks based on topics has gained recent popularity due to its specificity. Besides, these data networks are massive, continuous and evolving. Therefore, to address the above challenges we propose a dynamic framework for topic modelling and identifying influencers in the same process. It incorporates dynamic sampling, community detection and network statistics over graph data stream from a social media activity management application. Further, we compare the graph measures against each other empirically and observe that there is no evidence of correlation between the sets of users having large number of friends and the users whose posts achieve high acceptance (i.e., highly liked, commented and shared posts). Therefore, we propose a novel approach that incorporates a user's reachability and also acceptability by other users. Consequently, we improve on graph metrics by including a dynamic acceptance score (integrating content quality with network structure) for ranking influencers in micro-blogs. Additionally, we analysed the topic clusters' structure and quality with empirical experiments and visualization.Fundaçao para a Ciência e a Tecnologia, Grant/Award Number: UIDB/50014/202
Acetylcholine release and choline uptake by cuttlefish (Sepia officinalis) optic lobe synaptosomes
Acetylcholine (ACh), which is synthesized from choline (Ch), is believed to hold a central place in signaling mechanisms within the central nervous system (CNS) of cuttlefish (Sepia officinalis) and other coleoid cephalopods. Although the main elements required for cholinergic function have been identified in cephalopods, the transmembrane translocation events promoting the release of ACh and the uptake of Ch remain largely unsolved. The ACh release and Ch uptake were quantitatively studied through the use of in vitro chemiluminescence and isotopic methods on a subcellular fraction enriched in synaptic nerve endings (synaptosomes) isolated from cuttlefish optic lobe. The ACh release evoked by K+ depolarization was found to be very high (0.04 pmol ACh.s-(1).mg(-1) protein). In response to stimulation by veratridine, a secretagogue (a substance that induces secretion) that targets voltage-gated Na+ channels, the release rate and the total amount of ACh released were significantly lower, by 10-fold, than the response induced by KCl. The high-affinity uptake of choline was also very high (31 pmol Ch.min(-1).mg(-1) protein). The observed ACh release and Ch uptake patterns are in good agreement with published data on preparations characterized by high levels of ACh metabolism, adding further evidence that ACh acts as a neurotransmitter in cuttlefish optic lobe.FCTPOCTI/BSE/46721/2002SFRH/BPD/14677/2003SFRH/BD/1079/2000SFRH/BD/6403/2001SFRH/BD/18101/2004EC (to Y.D.) - LIPIDIET - QLK1-CT-2002-0017
Fish larvae quality descriptors: an appraisal of methods for red porgy Pagrus pagrus and grouper Epinephelus marginatus produced under different rearing conditions
Quality control in fish hatcheries is of paramount importance to achieve the desired characteristics of larvae and fry, either
for the market or release to the wild. Quality programmes are applied in a day to day basis having direct implications
for production management and final costs of product. Most common criteria used for larval quality assessment are
morphometrics, condition factor, histometrical indices, lipid analysis, nucleic acid ratios, enzyme activity and stress tests
Distributed Coding/Decoding Complexity in Video Sensor Networks
Video Sensor Networks (VSNs) are recent communication infrastructures used to capture and transmit dense visual information from an application context. In such large scale environments which include video coding, transmission and display/storage, there are several open problems to overcome in practical implementations. This paper addresses the most relevant challenges posed by VSNs, namely stringent bandwidth usage and processing time/power constraints. In particular, the paper proposes a novel VSN architecture where large sets of visual sensors with embedded processors are used for compression and transmission of coded streams to gateways, which in turn transrate the incoming streams and adapt them to the variable complexity requirements of both the sensor encoders and end-user decoder terminals. Such gateways provide real-time transcoding functionalities for bandwidth adaptation and coding/decoding complexity distribution by transferring the most complex video encoding/decoding tasks to the transcoding gateway at the expense of a limited increase in bit rate. Then, a method to reduce the decoding complexity, suitable for system-on-chip implementation, is proposed to operate at the transcoding gateway whenever decoders with constrained resources are targeted. The results show that the proposed method achieves good performance and its inclusion into the VSN infrastructure provides an additional level of complexity control functionality
Predicting olive phenology in Portugal in a warming climate
Prediction of flowering of olive trees should account for
chilling requirements, using an appropriate chilling unit
for the accounting of chilling accumulation. After chilling
requirements are satisfied, dormancy break takes place.
Thereafter, the trees enter the forcing phase, in which
the thermal time approach is used, but an appropriate
base temperature must be determined. Such a model was
developed, calibrated and validated for many olive cultivars
(De Melo-Abreu et al., 2004).
After flowering, the occurrence of developmental stages
may be predicted using a thermal time approach, but
for warm regions a saw-tooth model, which is a model
that reduces the effect of supra-optimal temperatures, is
mandatory (Garcia-Huidobro et al., :1.982).
According to the simulations of the model HadCM3,
developed by the Hadley Centre, global climate warming
will result in average temperature anomalies in winter, in
Continental Portugal, of about 2°C, in SRES scenarios 81
and 82, 3°C in scenario A2, and 4 °C in scenario A:tFI, by the
end of XXI century. (Miranda et al., 2006).
In this study, we discuss the prediction of flowering and
subsequent phenological stages and calculate and map
the times of occurrence of flowering under three warming
scenarios. No flowering or abnormal flowering events are
also predicted.Portuguese Foundation for Science and Technology (FCT) under Project Futurolive (PTDC/AGR-AAM/:1.04562/2008)
Diatraea saccharalis history of colonization in the Americas: The case for human-mediated dispersal
The sugarcane borer moth, Diatraea saccharalis, is one of the most important pests of sugarcane and maize crops in the Western Hemisphere. The pest is widespread throughout South and Central America, the Caribbean region and the southern United States. One of the most intriguing features of D. saccharalis population dynamics is the high rate of range expansion reported in recent years. To shed light on the history of colonization of D. saccharalis, we investigated the genetic structure and diversity in American populations using single nucleotide polymorphism (SNPs) markers throughout the genome and sequences of the mitochondrial gene cytochrome oxidase (COI). Our primary goal was to propose possible dispersal routes from the putative center of origin that can explain the spatial pattern of genetic diversity. Our findings showed a clear correspondence between genetic structure and the geographical distributions of this pest insect on the American continents. The clustering analyses indicated three distinct groups: one composed of Brazilian populations, a second group composed of populations from El Salvador, Mexico, Texas and Louisiana and a third group composed of the Florida population. The predicted time of divergence predates the agriculture expansion period, but the pattern of distribution of haplotype diversity suggests that human-mediated movement was most likely the factor responsible for the widespread distribution in the Americas. The study of the early history of D. saccharalis promotes a better understanding of range expansion, the history of invasion, and demographic patterns of pest populations in the Americas.Fil: Francischini, Fabricio J. B.. Universidade Estadual de Campinas. Instituto de BiologĂa; BrasilFil: Cordeiro, Erick M. G.. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Campos, Jaqueline B. de. Universidade Estadual de Campinas. Instituto de BiologĂa; BrasilFil: Alves Pereira, Alessandro. Universidade Estadual de Campinas; BrasilFil: Gomes Viana, JoĂŁo Paulo. Universidade Estadual de Campinas. Instituto de BiologĂa; BrasilFil: Wu, Xing. University of Illinois; Estados UnidosFil: Wei, Wei. University of Illinois; Estados UnidosFil: Brown, Patrick. University of Illinois; Estados UnidosFil: Joyce, Andrea. University of California; Estados UnidosFil: MurĂşa, MarĂa Gabriela. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Tucumán. Instituto de TecnologĂa Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. EstaciĂłn Experimental Agroindustrial "Obispo Colombres" (p). Instituto de TecnologĂa Agroindustrial del Noroeste Argentino; ArgentinaFil: Fogliata, Sofia Victoria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Tucumán. Instituto de TecnologĂa Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. EstaciĂłn Experimental Agroindustrial "Obispo Colombres" (p). Instituto de TecnologĂa Agroindustrial del Noroeste Argentino; ArgentinaFil: Clough, Steven J.. University of Illinois; Estados Unidos. United States Department of Agriculture; Estados UnidosFil: Zucchi, MarĂa Inmaculada. Universidade Estadual de Campinas; Brasi
Qualidade do azeite e sua relação com a cultivar e o clima em Portugal
A qualidade do azeite pode ser um elemento diferenciador, permitindo a prática de
melhores preços num mercado cada vez mais competitivo. Os constituintes que mais têm
sido apontados como tendo propriedades benĂ©ficas para a saĂşde sĂŁo a composição acĂdica
elevada em monoinsaturados, os valores elevados de tocoferĂłis, nomeadamente do atocoferol
(vitamina E), e de polifenĂłis. A cultivar, a temperatura e o Ăndice de maturação sĂŁo
variáveis que influenciam alguns dos parâmetros que estão associados à qualidade do azeite.
No âmbito do projeto Futurolive, financiado pela FCT, as cultivares Arbequina,
Cobrançosa, Galega, Picual e Verdeal foram ensaiadas em Mirandela, Santarém, Elvas e/ou
Moncarapacho (Algarve) durante 2 anos. Fizeram-se medições nas plantas, na atmosfera e
no solo. No azeite extraĂdo em todas as localizações e olivais, fizeram-se análises detalhadas
(análise sensorial, acidez, Ăndice de perĂłxidos, espectrofotometria, horas rancimat,
tocoferóis, polifenóis, esteróis, ácidos gordos totais, e triglicéridos).
Todas as amostras foram classificadas como azeite Virgem Extra, obtiveram na
análise sensorial uma classificação final igual ou superior a 6,5 e Ăndices de perĂłxidos, na
generalidade dos casos, muito inferiores a 20 meq 0 2 kg· 1
. As cultivares Picual e Verdeal
distinguiram-se por valores muito superiores de horas de rancimat, A 'Cobrançosa' e
'Galega' apresentam os valores mais elevados de a-tocoferol. A concentração de polifenóis e
de ácido oleico foi mais elevada na 'Verdeal' e 'Picual'.
A localização parece ter influência nos teores de a-tocoferol, sendo que em
Mirandela estes teores foram consistentemente mais elevados. Os teores de polifenĂłis sĂŁo
muito influenciados pelo Ăndice de maturação.
Relações entre a temperatura durante a maturação e as concentrações dos principais
parâmetros associados à qualidade são apresentadas e discutidas. Consequências do
aumento da temperatura devido às alterações climáticas são discutidas
Proteomic analysis of Chromobacterium violaceum and its adaptability to stress
Chromobacterium violaceum (C. violaceum) occurs abundantly in a variety of ecosystems, including ecosystems that place the bacterium under stress. This study assessed the adaptability of C. violaceum by submitting it to nutritional and pH stresses and then analyzing protein expression using bi-dimensional electrophoresis (2-DE) and Maldi mass spectrometry. Chromobacterium violaceum grew best in pH neutral, nutrient-rich medium (reference conditions); however, the total protein mass recovered from stressed bacteria cultures was always higher than the total protein mass recovered from our reference culture. The diversity of proteins expressed (repressed by the number of identifiable 2-DE spots) was seen to be highest in the reference cultures, suggesting that stress reduces the overall range of proteins expressed by C. violaceum. Database comparisons allowed 43 of the 55 spots subjected to Maldi mass spectrometry to be characterized as containing a single identifiable protein. Stress-related expression changes were noted for C. violaceum proteins related to the previously characterized bacterial proteins: DnaK, GroEL-2, Rhs, EF-Tu, EF-P; MCP, homogentisate 1,2-dioxygenase, Arginine deiminase and the ATP synthase β-subunit protein as well as for the ribosomal protein subunits L1, L3, L5 and L6. The ability of C. violaceum to adapt its cellular mechanics to sub-optimal growth and protein production conditions was well illustrated by its regulation of ribosomal protein subunits. With the exception of the ribosomal subunit L3, which plays a role in protein folding and maybe therefore be more useful in stressful conditions, all the other ribosomal subunit proteins were seen to have reduced expression in stressed cultures. Curiously, C. violeaceum cultures were also observed to lose their violet color under stress, which suggests that the violacein pigment biosynthetic pathway is affected by stress. Analysis of the proteomic signatures of stressed C. violaceum indicates that nutrient-starvation and pH stress can cause changes in the expression of the C. violaceum receptors, transporters, and proteins involved with biosynthetic pathways, molecule recycling, energy production. Our findings complement the recent publication of the C. violeaceum genome sequence and could help with the future commercial exploitation of C. violeaceum
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