3,676 research outputs found

    Charmed hadron signals of partonic medium

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    We present a short review of our results on the collectivity and the suppression pattern of charmed mesons in heavy-ion collisions based on the microscopic Hadron-String Dynamics (HSD) transport approach for different scenarios of charm interactions with the surrounding matter - the 'comover' dissociation by mesons with further recreation by D+Dbar channels and 'pre-hadronic' interaction scenarios. While at SPS energies the hadronic 'comover' absorption scenario is found to be compatible with the experimental data, the dynamics of c and cbar quarks at RHIC are dominated by partonic or 'pre-hadronic' interactions in the strongly coupled quark-gluon plasma stage and cannot be modeled by pure hadronic interactions. We find that the collective flow of charm in the purely hadronic scenario appears compatible with the data at SPS energies but underestimates the data at top RHIC energies. Thus, the large elliptic flow v2 of D mesons and the low R_AA(pT) of J/Psi seen experimentally at RHIC have to be attributed to early interactions of non-hadronic degrees of freedom. Simultaneously, we observe that non-hadronic interactions are mandatory in order to describe the narrowing of the J/Psi rapidity distribution from p+p to central Au+Au collisions at the top RHIC energy. We demonstrate additionally that the strong quenching of high-pT J/Psi's in central Au+Au collisions indicates that a fraction of final J/Psi mesons is created by a coalescence mechanism close to the phase boundary.Comment: Talk given at International Conference on Strangeness in Quark Matter (SQM 2008), Beijing, China, 6-10 Oct 200

    Whole-genome assembly of the coral reef Pearlscale Pygmy Angelfish (Centropyge vrolikii)

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    The diversity of DNA sequencing methods and algorithms for genome assemblies presents scientists with a bewildering array of choices. Here, we construct and compare eight candidate assemblies combining overlapping shotgun read data, mate-pair and Chicago libraries and four different genome assemblers to produce a high-quality draft genome of the iconic coral reef Pearlscale Pygmy Angelfish, Centropyge vrolikii (family Pomacanthidae). The best candidate assembly combined all four data types and had a scaffold N50 127.5 times higher than the candidate assembly obtained from shotgun data only. Our best candidate assembly had a scaffold N50 of 8.97 Mb, contig N50 of 189,827, and 97.4% complete for BUSCO v2 (Actinopterygii set) and 95.6% complete for CEGMA matches. These contiguity and accuracy scores are higher than those of any other fish assembly released to date that did not apply linkage map information, including those based on more expensive long-read sequencing data. Our analysis of how different data types improve assembly quality will help others choose the most appropriate de novo genome sequencing strategy based on resources and target applications. Furthermore, the draft genome of the Pearlscale Pygmy angelfish will play an important role in future studies of coral reef fish evolution, diversity and conservationUC Berkeley | Ref. S10RR029668UC Berkeley | Ref. S10RR02730

    Distribution of lipid compounds in sediments from Conceição Lagoon, Santa Catarina Island, Brazil

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    Lipid compounds from five sediment-water interface samples and a sediment core with 75 cm depth were used to assess sources of organic matter in Conceição Lagoon, located on Santa Catarina Island. The results which were based on the molar C:N:P ratios, relative abundance of sterols (dominated by the C27 sterols), n-alkanols (0.2-1.2 µg g-1), n-alkanes (0.4-5.0 µg g-1) and the Carbon Preference Index (CPI), indicated that the organic matter is predominantly of terrestrial origin (C/N > 10 and CPI > 2). Total phosphorus (TP, average 5.20 µmol g-1) and organic carbon (TOC, average 2.90 mmol g-1) contents were well correlated with the silt and clay fractions at all locations. In the sediment core, chronologically dated with the radionuclide 210Pb, the depth interval from 55 to 75 cm was dominated by the sand fraction (> 50%). However, parameters such as TOC, TP and n-alkane contents increased considerably at this depth suggesting a change in organic matter input sources

    Labyrinthine fístulae in chronic otitis media with cholesteatoma

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    The chronic otitis media with cholesteatoma (COMC) may evoluate to intracranial and extra cranial complications, including the labyrithine fístulae. In this study, we present the evolution of our patients with labyrinthine fístulae. STUDY DESIGN: Clinical prospective. MATERIAL AND METHOD: Ten out 82 patients with COMC had labyrinthine fístulae and underwent surgery from January/2001 to April/2002. They were assessed by clinical exam, computed tomography scans, and pre and postoperative audiogram. RESULTS: Hearing loss, otorrhea, tinnitus and dizziness were present in 100%, 90%,80%, and 40% of the cases. In one patient the fístulae was seen only in the coronal CT-scan, in another patient the fístulae was not seen neither in coronal nor axial images. Among the patients who had tinnitus, 66% referred improvement of this complaint after surgery. DISCUSSION: in the cases without invasion of the perilymphatic space, we noticed a tendency of improvement of the postoperative audiogram pattern and clinical outcome. In the extensive fístulae, on the other hand, there were no clinical changes. CONCLUSION: The CT-scan remains the best exam to assess the COMC with 90% of sensitivity for labyrinthine fístulae. In the stage II we had a good postoperative outcome.A otite média crônica colesteatomatosa (OMCC) pode cursar com complicações intra e/ou extracranianas, entre elas a fístula labiríntica. Neste trabalho, mostramos a incidência e a evolução dos casos de fístula labiríntica decorrentes da OMCC em nosso serviço. FORMA DE ESTUDO: Clínico prospectivo. MATERIAL E MÉTODO: Dez pacientes com fístula labiríntica, do total de 82 pacientes com OMCC, foram submetidos à cirurgia no período de janeiro de 2001 a abril de 2002 e avaliados através de exame otorrinolaringológico completo, tomografia computadorizada e audiometria pré e pós-operatória. RESULTADOS: Perda auditiva, otorréia, zumbido e vertigem estavam presentes em 100%, 90%, 80% e 40% dos casos respectivamente na avaliação clínica pré-operatória. Em um paciente a fístula aparecia apenas nos cortes tomográficos coronais e tivemos um caso de falso-negativo. Dos pacientes com zumbido, 66% apresentaram melhora deste quadro no pós-operatório. DISCUSSÃO: Nos casos de fístula sem invasão do espaço perilinfático (até grau II), notamos uma tendência de melhora dos quadros clínico e audiométrico após a cirurgia. Nas fístulas extensas, por outro lado, o resultado audiométrico se manteve inalterado. CONCLUSÃO: A tomografia continua sendo o exame de escolha para os quadros de OMCC com sensibilidade de 90% para fístulas labirínticas. Nas fístulas grau II a cirurgia apresenta bom resultado funcional.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Otorrinolaringologia e Distúrbios da Comunicação HumanaUNIFESP, EPM, Depto. de Otorrinolaringologia e Distúrbios da Comunicação HumanaSciEL

    South American Expert Roundtable : increasing adaptive governance capacity for coping with unintended side effects of digital transformation

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    This paper presents the main messages of a South American expert roundtable (ERT) on the unintended side effects (unseens) of digital transformation. The input of the ERT comprised 39 propositions from 20 experts representing 11 different perspectives. The two-day ERT discussed the main drivers and challenges as well as vulnerabilities or unseens and provided suggestions for: (i) the mechanisms underlying major unseens; (ii) understanding possible ways in which rebound effects of digital transformation may become the subject of overarching research in three main categories of impact: development factors, society, and individuals; and (iii) a set of potential action domains for transdisciplinary follow-up processes, including a case study in Brazil. A content analysis of the propositions and related mechanisms provided insights in the genesis of unseens by identifying 15 interrelated causal mechanisms related to critical issues/concerns. Additionally, a cluster analysis (CLA) was applied to structure the challenges and critical developments in South America. The discussion elaborated the genesis, dynamics, and impacts of (groups of) unseens such as the digital divide (that affects most countries that are not included in the development of digital business, management, production, etc. tools) or the challenge of restructuring small- and medium-sized enterprises (whose service is digitally substituted by digital devices). We identify specific issues and effects (for most South American countries) such as lack of governmental structure, challenging geographical structures (e.g., inclusion in high-performance transmission power), or the digital readiness of (wide parts) of society. One scientific contribution of the paper is related to the presented methodology that provides insights into the phenomena, the causal chains underlying “wanted/positive” and “unwanted/negative” effects, and the processes and mechanisms of societal changes caused by digitalization

    Relação entre a geodiversidade intrínseca e a estruturação de habitat na escala do geossítio: exemplos na Serra do Segredo e nas Pedras das Guaritas (Caçapava do Sul, RS, Brasil)

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    Geosites are points or areas that represent better the geodiversity of a territory, i.e. its natural range of geological elements. Among the criteria used for the quantitative assessment of geosites is its relevance for structuring habitat, related with its functional or ecological support value. This paper aims at presenting the relationships between the intrinsic geodiversity of a geosite (its geological features) and the existing habitat diversity. Thus, the geosites Serra do Segredo and Pedras das Guaritas, both located in Caçapava do Sul, south-central Rio Grande do Sul State, were analyzed in detail. Literature review, satellite and aerial photograph images were analyzed, as well as data collected during fieldtrips in different seasons. It is highlighted here the importance of depositional, tectonic and weathering features, at the geosite scale, for the structuring and maintaining various types of environments and organisms: from lichens to forest fragments, from amphibian tadpoles to medium-sized mammals.Os geossítios são locais ou áreas que melhor representam a geodiversidade de um território, ou seja, a variedade natural de elementos geológicos. Entre os critérios de avaliação quantitativa de geossítios está sua importância na estruturação de habitat, relacionado a seu valor funcional ou de suporte ecológico. Este trabalho objetiva apresentar as relações entre a geodiversidade intrínseca (de feições geológicas) de um geossítio e a diversidade de habitat e/ou abrigos existentes. Para isso, analisaram-se informações da bibliografia, imagens de satélite, fotografias aéreas e dados provenientes de saídas a campo em diferentes épocas do ano nos geossítios Serra do Segredo e Pedras das Guaritas, ambos no município de Caçapava do Sul, centro-sul do Rio Grande do Sul. Demonstra-se aqui a importância de feições deposicionais, deformacionais e intempéricas, na escala do geossítio, para a estruturação e a manutenção de diversos tipos de ambientes e organismos: de líquenes a fragmentos florestais, de formas jovens de anfíbios a mamíferos de médio porte

    Uma Avaliação do Esquema de Gerenciamento de Chave Baseado em Identidade Identity Key Management

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    A segurança é um dos principais desafios nas Redes Ad Hoc Móveis (MANETs - Mobile Ad Hoc Networks). As características naturais das MANETs tornam essas redes altamente vulneráveis a muitos ataques, da camada física até a camada de aplicação. Exitem diversos algoritmos e protocolos para tratar essas ameaças. Todos esses algoritmos têm um elemento comum, o uso da criptografia. Entre os sistemas criptográficos encontrados na literatura, os baseados em identidade parecem melhor se adaptar ao paradigma das MANETs. Suas principais vantagens são o baixo custo computacional e a sobrecarga reduzida. Estre trabalho apresenta uma avaliação do principal esquema criptográfico baseado em identidade para as MANETs, o Identity Key Management (IKM). A avaliação foi realizada considerando a renovação e revogação de chaves e a presença de ataques de falsa acusação. Os resultados mostram que o IKM é vulnerável a este ataque e o particionamento da rede pode levá-la a um estado instável

    The strengths and weaknesses of species distribution models in biome delimitation

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    This is the final published version, also available from Frontiers via the DOI in this record.Aim: The aim was to test whether species distribution models (SDMs) can reproduce major macroecological patterns in a species-rich, tropical region and provide recommendations for using SDMs in areas with sparse biotic inventory data. Location: North-east Brazil, including Minas Gerais. Time period: Present. Major taxa studied: Flowering plants. Methods: Species composition estimates derived from stacked SDMs (s-SDMs) were compared with data from 1,506 inventories of 933 woody plant species from north-east Brazil. Both datasets were used in hierarchical clustering analyses to delimit floristic units that correspond to biomes. The ability of s-SDMs to predict the identity, functional composition and floristic composition of biomes was compared across geographical and environmental space. Results: The s-SDMs and inventory data both resolved four major biomes that largely corresponded in terms of their distribution, floristics and function. The s-SDMs proved excellent at identifying broad-scale biomes and their function, but misassigned many individual sites in complex savanna–forest mosaics. Main conclusions: Our results show that s-SDMs have a unique role to play in describing macroecological patterns in areas lacking inventory data and for poorly known taxa. s-SDMs accurately predict floristic and functional macroecological patterns but struggle in areas where non-climatic factors, such as fire or soil, play key roles in governing distributions.Natural Environment Research Council (NERC)Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorConselho Nacional de Desenvolvimento Científico e TecnológicoRoyal Societ

    Produção de biomassa e características fisiológicas do feijoeiro cv. Pérola na safra de inverno.

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    O objetivo deste trabalho foi avaliar os índices fisiológicos de plantas de feijão cv. Pérola semeadas em diferentes datas, na safra de inverno

    Low bone mineral density among HIV-infected patients in Brazil

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    Decrease in bone mineral density (BMD) has been a complication among people living with HIV/AIDS. To investigate the prevalence of osteopenia/osteoporosis among HIV-infected people living in São Paulo city, we studied 108 HIV-infected patients (79 men and 29 women). We extracted data from patients’ medical records and BMD was measured by dual-energy X-ray absorptiometry (DXA). Median age of participants was 42 years (interquartile range [IQR] 36-48 years), and the median time since HIV diagnosis was 4.01 years (IQR 2-11 years). Patients had acquired HIV primarily by the sexual route (men who have sex with men 44%, heterosexual 49%). Median age, duration of HIV infection, duration of ART and CD4 nadir were similar for men and women. Plasma viral load was undetectable for 53 patients (49%). Median CD4 T cell count was 399 cells/µL (IQR 247 - 568). Twenty five patients (23%) had LBMD, and there was no statistically significant difference between men and women
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