977 resultados para curves of genus three


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In the study, we establish centennial records of anthropogenic lead pollution at different locations in the North Atlantic (Iceland, USA, and Europe) by means of lead deposited in shells of the long-lived bivalve Arctica islandica. Due to local oceanographic and geological conditions we conclude that the lead concentrations in the Icelandic shell reflect natural influxes of lead into Icelandic waters. In comparison, the lead profile of the US shell is clearly driven by anthropogenic lead emissions transported from the continent to the ocean by westerly surface winds. Lead concentrations in the European North Sea shell, in contrast, are dominantly driven by local lead sources resulting in a much less conspicuous 1970s gasoline lead peak. In conclusion, the lead profiles of the three shells are driven by different influxes of lead, and yet, all support the applicability of Pb/Ca analyses of A. islandica shells to reconstruct location specific anthropogenic lead pollution.

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High-, i.e. 15-140-yr-resolution climate records from sediment cores 23071, 23074, and PS2644 from the Nordic Seas were used to recon:;truct changes in the surface and deep water circulation during marine isotope stages 1-5.1, i.e. the last 82 000 yr. From this the causal links between the paleoceanographic signals and the Dansgaard-Oeschger events 1-21 revealed in 0180-ice-core records from Greenland were determined. The stratigraphy of the cores is based on the planktic 0180 curves, the minima of which were directly correlated with the GISP2-0180 record, numerous AMS 14C ages, and some ash layers. The planktic d18O and dl3C curves of all three cores reveal numerous meltwater events, the most pronounced of which were assigned to the Heinrich events 1-6. The meltwater events, among other things also accompanied by cold sea surface temperatures and high IRD concentration, correlate with the stadial phases of the Dansgaard-Oeschger cycles and in the western Iceland Sea also to colder periods or abrupt drops in 0180 within a few longer interstadials. Besides being more numerous, the meltwater events also show isotope values lighter in the Iceland Sea than in the central Norwegian Sea, especially if compared to core 23071. This implies a continuous inflow of relative warm Atlantic water into the Norwegian Sea and a cyclonic circulation regime.

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Purpose – The paper aims to conceptualise cosmopolitanism drivers from the third-level power perspective by drawing on Lukes’ (1974; 2005) theory of power. In addition, the paper aims to investigate the relationship between entrepreneurs’ cosmopolitan dispositions and habitus, i.e. a pattern of an individual’s demeanour, as understood by Bourdieu. Design/methodology/approach – This conceptual paper makes use of Bourdieu’s framework (habitus) by extending it to the urban cosmopolitan environment and linking habitus to the three-dimensional theory of power and, importantly, to the power’s third dimension – preference-shaping. Findings – Once cosmopolitanism is embedded in the urban area’s values, this creates multiple endless rounds of mutual influence (by power holders onto entrepreneurs via political and business elites, and by entrepreneurs onto power holders via the same channels), with mutual benefit. Therefore, mutually beneficial influence that transpires in continuous support of a cosmopolitan city’s environment may be viewed as one of the factors that enhances cosmopolitan cities’ resilience to changes in macroeconomic conditions. Originality/value – The paper offers a theoretical model that enriches the understanding of the power-cosmopolitanism-entrepreneurship link, by emphasising the preference-shaping capacity of power, which leads to the embedment of cosmopolitanism in societal values. As a value shared by political and business elites, cosmopolitanism is also actively promoted by entrepreneurs through their disposition and habitus. This ensures not only their willing compliance with power and the environment, but also their enhancement of favourable business conditions. Entrepreneurs depart from mere acquiescence (to power and its explicit dominance), and instead practice their cosmopolitan influence by active preference-shaping.

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The development of accurate modeling techniques for nanoscale thermal transport is an active area of research. Modern day nanoscale devices have length scales of tens of nanometers and are prone to overheating, which reduces device performance and lifetime. Therefore, accurate temperature profiles are needed to predict the reliability of nanoscale devices. The majority of models that appear in the literature obtain temperature profiles through the solution of the Boltzmann transport equation (BTE). These models often make simplifying assumptions about the nature of the quantized energy carriers (phonons). Additionally, most previous work has focused on simulation of planar two dimensional structures. This thesis presents a method which captures the full anisotropy of the Brillouin zone within a three dimensional solution to the BTE. The anisotropy of the Brillouin zone is captured by solving the BTE for all vibrational modes allowed by the Born Von-Karman boundary conditions.

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Objective: The aim of the study is to examine the distribution of integrated covariate and its association with blood pressure (BP) among children in Anhui province, China, and assess the predictive value of integrated covariate to children hypertension. Methods: A total of 2,828 subjects (1,588 male and 1,240 female) aged 7-17 years participated in this study. Height, weight, waistline, hipline and BP of all subjects were measured, obesity and overweight were defined by an international standard, specifying the measurement, the reference population, and the age and sex specific cut off points. High BP status was defined as systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) > 95th percentile for age and gender. Results: Our results revealed that the prevalence of children hypertension was 11.03%, the SBP and DBP of obesity group were significantly higher than that of normal group. Anthropometric obesity indices such as body mass index (BMI) were positively correlated with SBP and DBP. Integrated covariate had a better performance than the single covariate in the receiver-operating characteristic (ROC) curve, the cut-off value; the sensitivity and the specificity of the integrated covariate were 0.112, 0.577, 0.683, respectively. Conclusion: Integrated covariate is a simple and effective anthropometric index to identify childhood hypertension.

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Background: Despite improvements in child health, malnutrition still remains one of the main public health challenges in Iran. Objectives: The aim of this study was to compare under nutrition among under-five children with regard to ethnicity in rural area in north Iran. Patients and Methods: In three cross-sectional studies 7575 subjects in three time-periods including 2339 children in 1998, 2749 in 2004, and 2487 in 2013, were evaluated. All under-five-children in 20 out of 118 villages were chosen by random sampling and assessed. Under nutrition was defined as underweight, stunting and wasting lower than -2 SD (Z < -2 SD). Results: Generally, stunting was declined 17.1% and underweight and wasting were increased 0.9% and 1%, respectively during 15 years (1998 - 2013). Underweight increased 0.5% in Fars-natives and 3.2% in Turkmans and it was decreased 0.9% in Sistanis. Statistical difference in Turkman children among the three stages of the study was significant (P = 0.001). Stunting has decreased 28.7% in Fars-natives and 35.1% in Sistanis, it was increased 9.3% in Turkman group. Statistical differences among three stages in inter-ethnic groups were significant (P = 0.001 for all). Compared the group with good economic status, the odds ratio was 1.831 in poor economic group (P = 0.001). The risk of under nutrition in Sistanis was 1.754 times more than in Fars-natives (P = 0.001). Conclusions: Under nutrition remains one of the main health problems in under-five-year children in north Iran being more common in Sistani children. Stunting in Sistani children deeply decreased while in Turkman children slightly increased during the 15-year period study. Poor economic status is a risk factor for under nutrition in this area.

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Purpose: To investigate the phytochemistry and cytotoxic activity of stem bark extracts from Genus dolichocarpa and Duguetia chrysocarpa - two species of the Annonaceae family. Methods: The crude ethanol bark extracts (EtOH) of the plants were obtained by maceration. The crude extracts were suspended in a mixture of methanol (MeOH) and water (H2O) (proportion 3:7 v/v) and partitioned with hexane, chloroform (CHCl3) and ethyl acetate (AcOEt) in ascending order of polarity to obtain the respective fractions. The extracts were evaluated on thin layer chromatography (TLC) plates of silica gel to highlight the main groups of secondary metabolites. Cytotoxicity was tested against human tumor cell lines - OVCAR-8 (ovarian), SF-295 (brain) and HCT-116 (colon) - using 3- (4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Results: The screening results demonstrated that all the extracts were positive for the presence of flavonoids and tannins. The presence of alkaloids also was detected in some extracts. The hexane extract of A. dolichocarpa showed the strongest cytotoxicity against HCT-116 with cell growth inhibition of 89.02 %. Conclusion: The findings demonstrate for the first time the cytotoxic activity of the extracts of A. dolichocarpa and D. chrysocarpa, thus providing some evidence that plants of the Annonaceae family are a source of active secondary metabolites with cytotoxic activity.

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We have simulated, using parallel tempering, the three-dimensional Ising spin glass model with binary couplings in a helicoidal geometry. The largest lattice (L520) has been studied using a dedicated computer (the SUE machine). We have obtained, measuring the correlation length in the critical region, strong evidence for a second-order finite-temperature phase transition, ruling out other possible scenarios like a KosterlitzThouless phase transition. Precise values for the ν and ƞ critical exponents are also presented.

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In recent decades, the national and international media contexts, in particular television media, significantly changed. The role that social networks, in particular Facebook, have taken as a content diffusion platform is unquestionable. Nowadays, traditional media (radio, newspaper, television) use the Web’s potential to distribute news content (Canelas, 2011). Currently, all TV news channels in Portugal have a website or a page on social networks. TV stations have increased communication channels with the public on digital platforms and study strategies that promote the participation and interaction with the news content (Cazajeira, 2015). The TV / Internet convergence will not only reach the content, but also the consumer, who becomes an interactive and participative audience. This reality imposes on journalism a continuous and updated news production system, dependent on a user being permanently connected to the Internet (Cazajeira, 2015). In fact, a report launched by an autonomous institution that has the function of supervising and regulating the media Portugal (ERC, 2015), confirms the relevance that social media has assumed in the publication and consumption of news. Social networks are recognised as one of the most important means for news media consultation, right after television, and the practice of sharing news is very common among consumers of online news in Portugal. Furthermore, when compared to other countries analysed by Reuters Institute (Newman, Levy, & Nielsen, 2015), Portuguese consumers are those who make the most comments to online news, preferring social networks to news sites. Considering the importance of new online platforms for journalism, this study aims to present a quantitative analysis of user participation on the Facebook pages of the three Portuguese TV news channels, specifically RTP3, SIC Notícias and TVI24, between 8 and 14 February 2016. To track this participation, the following parameters were used: the "like" button as a way to study the demonstration of publication interest; "sharing" of a particular element, be it a photo, a video or a text, on the user Timeline, the Timeline of a friend or by private message. This monitoring is important to understand the dissemination of news content; and the comments area. The number of comments will help understand the dynamics and the discussion that the publication has on the public. The results of 1063 posts indicate that of the analysed parameters - "Like", "Comment", and "Share" – the one with the greatest power of participation among the users of the pages of the three Portuguese TV news channels is the "Like" system, followed by "Share" and then "Comment". The theme that generates the most user participation with "Likes" and “Comments” parameters are "Science and Technology", “Education” and “Humorous/Satirical/Unusual”. Finally, the publications available end of the night (10pm-1am) has better participation rates.

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mRNA translation in many ciliates utilizes variant genetic codes where stop codons are reassigned to specify amino acids. To characterize the repertoire of ciliate genetic codes, we analyzed ciliate transcriptomes from marine environments. Using codon substitution frequencies in ciliate protein-coding genes and their orthologs, we inferred the genetic codes of 24 ciliate species. Nine did not match genetic code tables currently assigned by NCBI. Surprisingly, we identified a novel genetic code where all three standard stop codons (TAA, TAG, and TGA) specify amino acids in Condylostoma magnum. We provide evidence suggesting that the functions of these codons in C. magnum depend on their location within mRNA. They are decoded as amino acids at internal positions, but specify translation termination when in close proximity to an mRNA 3' end. The frequency of stop codons in protein coding sequences of closely related Climacostomum virens suggests that it may represent a transitory state.mRNA translation in many ciliates utilizes variant genetic codes where stop codons are reassigned to specify amino acids. To characterize the repertoire of ciliate genetic codes, we analyzed ciliate transcriptomes from marine environments. Using codon substitution frequencies in ciliate protein-coding genes and their orthologs, we inferred the genetic codes of 24 ciliate species. Nine did not match genetic code tables currently assigned by NCBI. Surprisingly, we identified a novel genetic code where all three standard stop codons (TAA, TAG, and TGA) specify amino acids in Condylostoma magnum. We provide evidence suggesting that the functions of these codons in C. magnum depend on their location within mRNA. They are decoded as amino acids at internal positions, but specify translation termination when in close proximity to an mRNA 3' end. The frequency of stop codons in protein coding sequences of closely related Climacostomum virens suggests that it may represent a transitory state.

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O sorgo sacarino [Sorghum bicolor (L.) Moench] se destaca como cultura complementar à cana-de-açúcar Saccharum spp. na produção de etanol, uma vez que este possui colmos suculentos com presença de açúcares diretamente fermentescíveis. Em decorrência deste fato, existe a necessidade de se analisar as propriedades do sorgo, a fim de atender às demandas da agroindústria. No presente trabalho, buscou-se desenvolver e estudar as curvas de maturação de sete cultivares de sorgo sacarino em dez épocas de colheita. Os resultados mostram que houve diferença significativa para cultivares e épocas de colheita para todos os parâmetros (p≤0,01). Quanto aos teores de açúcares, as cultivares BRS508, XBWS80147 e CMSXS629 apresentaram as maiores médias para as variáveis açúcares redutores totais (ART) e açúcares totais recuperáveis (ATR). Em relação à produção de etanol por tonelada de biomassa, as cultivares BRS 508 e a CMSXS629 apresentaram os melhores resultados.

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Bifidobacteria is amongst one of the health promoting bacteria. The role of this important probiotic genera can be elucidated by understanding its genome. Comparative analysis of the whole genus of these bacteria can reveal their adaptation to a diverse host range. This study comprises of four research projects. In the first study, a reference library for genus Bifidobacterium was prepared. The core genes in each genus were selected based on a newly proposed statistical definition of core genome. Comparative analysis of Bifidobacterium with another probiotic genus Lactobacillus revealed the metabolic characteristics of genus Bifidobacterium. The second study investigated the immunomodulatory role of a B. bifidum strain TMC3115. The analysis of TMC3115 provided insights into its extracellular structures which might have their role in host interaction and immunomodulation. The study highlighted the variability among these genomes just not on species level but also on strain level in terms of host interaction. The last two studies aim to inspect the relationship between bifidobacteria and its host diet. Bifidobacteria, are both host- and niche-specific. Such adaptation of bifidobacterial species is considered relevant to the intestinal microecosystem and hosts’ oligosaccharides. Many species should have co-evolved with their hosts, but the phylogeny of Bifidobacterium is dissimilar to that of host animals. The discrepancy could be linked to the niche-specific evolution due to hosts’ dietary carbohydrates. The distribution of carbohydrate-active enzymes, in particular glycoside hydrolases (GHs) that metabolize unique oligosaccharides was examined. When bifidobacterial species were classified by their distribution of GH genes, five groups arose according to their hosts’ feeding behaviour. The distribution of GH genes was only weakly associated with the phylogeny of the host animals or with genomic features such as genome size. Thus, the hosts’ dietary pattern is the key determinant of the distribution and evolution of GH genes.

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La colonna vertebrale è la principale sede di metastasi, le quali possono alterare la normale distribuzione dei tessuti ossei e ridurre la capacità della vertebra di sostenere carichi. L’instabilità spinale causata dalle metastasi, tuttavia, è di difficile determinazione. La caratterizzazione meccanica delle vertebre metastatiche permetterebbe di identificare e, di conseguenza trattare, quelle ad alto rischio di frattura. In questo studio, ho valutato il comportamento meccanico a rottura di vertebre umane affette da metastasi misurando in vitro il campo di deformazione. Undici provini, costituiti da due vertebre centrali, una metastatica e una sana, sono stati preparati e scansionati applicando carichi graduali di compressione in una micro-tomografia computerizzata (μCT). Le deformazioni principali sono state misurate attraverso un algoritmo globale di Digital Volume Correlation (DVC) e successivamente sono state analizzate. Lo studio ha rivelato che le vertebre con metastasi litiche raggiungono deformazioni maggiori delle vertebre sane. Invece, le metastasi miste non assicurano un comportamento univoco in quanto combinano gli effetti antagonisti delle lesioni litiche e blastiche. Dunque la valutazione è stata estesa a possibili correlazioni tra il campo di deformazione e la microstruttura della vertebra. L'analisi ha identificato le regioni in cui parte la frattura (a più alta deformazione), senza identificare, in termini microstrutturali, una zona preferenziale di rottura a priori. Infatti, alcune zone con un pattern trabecolare denso, presunte più rigide, hanno mostrato deformazioni maggiori di quelle dei tessuti sani, sottolineando l’importanza della valutazione della qualità del tessuto osseo. Questi risultati, generalizzati su un campione più ampio, potrebbero essere utilizzati per implementare nuovi criteri negli attuali sistemi di valutazione dell'instabilità spinale.