737 research outputs found

    Zooplankton biomass, abundance and diversity in a shelf area of Portugal (the Berlenga Marine Natural Reserve).

    Get PDF
    During November 1997 and May 1998, zooplankton samples were collected with other environmental data along the shelf area of Berlenga marine natural reserve (MNR) (NW Portugal). Copepods contributed > 70 % to the total zooplankton community. In November the dominant species of copepods were Paracalanus parvus, Temora stylifera and Centropages chierchiae with larvaceans and the cladocerans Penilia avirostris also abundant. The meroplankton was dominated by echinoderms. In May the dominant species of copepods were Pseudocalanus elongatus and Acartia clausi, Centropages typicus, and Calanus helgolandicus, with barnacle larvae and the pisces larvae also abundant. The islands influence was represented in the results by the increase in diversity and meroplankton’s relative importance at the sampling stations in the vicinity of the islands

    Enforcing RFID data visibility restrictions using XACML security policies

    Get PDF
    Radio Frequency Identification (RFID) technology allows automatic data capture from tagged objects moving in a supply chain. This data can be very useful if it is used to answer traceability queries, however it is distributed across many different repositories, owned by different companies. Discovery Services (DS) are designed to assist in retrieving the RFID data relevant for traceability queries while enforcing sharing policies that are defined and required by participating companies to prevent sensitive data from being exposed. In this paper we define an interface for Supply Chain Authorization (SC-Az) and describe the implementation of two visibility restriction mechanisms based on Access Control Lists (ACLs) and Capabilities. Both approaches were converted to the standard eXtensible Access Control Markup Language (XACML) and their correctness and performance was evaluated for supply chains with increasing size

    Caracterização do efetivo caprino da raça Boer em Portugal

    Get PDF
    A raça caprina Boer, originária da Africa do Sul, é considerada uma das raças mais importantes para a produção de carne, apresentando uma excelente capacidade de adaptação, sendo por isso explorada, com sucesso, em várias zonas do globo, com condições meteorológicas muito variadas. Atualmente, a exploração de caprinos desta raça em Portugal ainda tem uma expressão bastante diminuta, tendo sido concluída a criação do Livro Genealógico (LG) da raça Boer em novembro de 2015, gerido pela APCRB – Associação Portuguesa de Caprinicultores da Raça Boer. Pretendeu-se com este estudo contribuir para a caracterização do efetivo caprino Boer existente em Portugal. O trabalho baseou-se nos dados obtidos em visitas realizadas às explorações, no processo de registo dos animais no LG da raça. Atualmente, em Portugal, existem nove criadores, mas apenas oito com animais inscritos no LG, com um efetivo total de 142 animais, 112 fêmeas e 30 machos. Os animais são nascidos em Portugal (48,6%), e importados, principalmente da Alemanha (36,6%), mas também da Holanda (12,7%) e Espanha (2,1%). As explorações encontram-se distribuídas pelos concelhos de Alandroal, Benavente, Vidigueira, Campo-Maior, Coruche, Évora, Portalegre, Porto de Mós e Vila Nova de Foz Côa. Os criadores, na sua maioria, exploram os animais em sistema semi-intensivo, com base no pastoreio direto e suplementação, com feno e alimento composto comercial. Apenas um criador explora os animais em sistema extensivo. Regra geral, não existem épocas de cobrição definidas. Os machos são mantidos junto das fêmeas e a beneficiação realiza-se por cobrição natural. Excecionalmente, no ano de 2016, dois criadores recorreram à inseminação artificial, por laparoscopia, com sémen importado da Austrália. A dimensão dos efetivos por exploração é diversa, variando entre quatro e trinta animais, com um valor médio de dezoito animais. O efetivo nacional é relativamente jovem, predominando animais com idades entre um e três anos, representando 85% do efetivo. O número de nascimentos aumentou entre 2007 e 2013, ano em que se registou o valor mais elevado (42), tendo este vindo a decrescer posteriormente. A inexistência de épocas de cobrição definidas reflecte-se numa distribuição dos nascimentos ao longo de todo o ano. A pontuação obtida na classificação morfológica dos animais, efetuada até ao momento, permitiu que a sua totalidade fosse inscrita no LG. Apesar de uma expressão ainda diminuta do efetivo Boer em Portugal, a expansão desta raça afigura-se interessante, dadas as excelentes características destes animais para a produção de carne.info:eu-repo/semantics/publishedVersio

    Applicability of ecological evaluation tools in estuarine ecosystems: the case of the lower Mondego estuary (Portugal)

    Get PDF
    Abstract In accordance with the Water Framework Directive guidelines (WFD, 2000, European Communities Official Journal L327 2000/60/EC), classification schemes and ecological evaluation tools (based on benthic invertebrate fauna data sets from 1990 to 2002) were applied in the lower Mondego estuary. Two distinct scenarios could be tested due to the implementation of mitigation practices in 1999, following a long eutrophication process, which started by the early 1980s. Some discrepancies in the results were found by the application of the different indices. The AMBI index (accounting for taxonomic composition) and the ABC method (accounting for abundance and biomass k-dominance patterns) classifications often disagreed with those based on species diversity (Margalef and Shannon-Wiener). The ambiguous results made the classification a complex task to achieve, contrary to the Directive’s objective of maintaining it simple and clear. Our results suggest the necessity of adjusting some of the indices and their ranges to estuarine characteristics, namely to account the typical dominance and abundance of some particular species. These aspects are not taken into consideration by some of the indices proposed, which are more adapted to typical marine conditions. Based on our results, these widely applied indices might still improve their efficiency in estuarine systems allowing their use in the resembling types already established within the new Directive agenda

    Does Big Data Require Complex Systems? A Performance Comparison Between Spark and Unicage Shell Scripts

    Full text link
    The paradigm of big data is characterized by the need to collect and process data sets of great volume, arriving at the systems with great velocity, in a variety of formats. Spark is a widely used big data processing system that can be integrated with Hadoop to provide powerful abstractions to developers, such as distributed storage through HDFS and resource management through YARN. When all the required configurations are made, Spark can also provide quality attributes, such as scalability, fault tolerance, and security. However, all of these benefits come at the cost of complexity, with high memory requirements, and additional latency in processing. An alternative approach is to use a lean software stack, like Unicage, that delegates most control back to the developer. In this work we evaluated the performance of big data processing with Spark versus Unicage, in a cluster environment hosted in the IBM Cloud. Two sets of experiments were performed: batch processing of unstructured data sets, and query processing of structured data sets. The input data sets were of significant size, ranging from 64 GB to 8192 GB in volume. The results show that the performance of Unicage scripts is superior to Spark for search workloads like grep and select, but that the abstractions of distributed storage and resource management from the Hadoop stack enable Spark to execute workloads with inter-record dependencies, such as sort and join, with correct outputs.Comment: 10 pages, 14 figure

    Infection characteristics of a trematode in an estuarine isopod: influence of substratum

    Get PDF
    The estuarine isopod Cyathura carinata is a second intermediate host to microphallid trematodes, which use mud snails Hydrobia spp. and shorebirds as respectively first intermediate and final hosts. To identify processes responsible for infection patterns observed in C. carinata, a short-term microcosm experiment was conducted with both macroinvertebrates and one of their common parasites – Maritrema subdolum. Fine sand collected from two different shallow water sites was used to test if sediment type could affect infection rates. After 7 days at 25 °C, C. carinata from the substratum with the highest proportion of particles µm were more surface active and obtained significantly more M. subdolum individuals than isopods from the other sediment type. No parasite-induced effects on the hosts were found during this short-term experiment. The distribution pattern of microphallid cysts and mesocercariae inside the isopods revealed that M. subdolum cercariae primarily penetrated through the pleopods and afterwards located themselves in the middle-posterior region of the host’s body. Even if it was not possible to identify the factor responsible for the observed infection patterns (cercariae production and/or host behaviour), the results of this experiment indicate that small-scale factors, such as differences in substratum and associated features, may have considerable impact on infections of host populations

    Estuarine production of resident and nursery fish species: Conditioning by drought events?

    Get PDF
    The production of resident (Pomatoschistus minutus and Pomatoschistus microps) and marine juvenile fish species using the Mondego estuary (central Portugal) as nursery grounds (Dicentrarchus labrax, Platichthys flesus, Solea solea), was assessed in order to: (1) understand the potential of the estuary for fish production; (2) know the production of nursery fish species likely to be exported to the coastal stocks; and (3) how anthropogenic and natural stress could influence the estimated production. Sampling occurred from June 2003 to May 2006 and together the 5 species in study comprised around 70% of the whole fish community numbers and biomass. Increasing drought conditions were observed, starting with a normal hydrological year in 2003 until attaining a severe drought in 2005, which resulted in low river discharges (1/3 of the mean river discharges in 2003). Additionally, high water temperatures were observed in 2003 and 2005 (24 and 26 °C, night temperatures). The secondary production was estimated using the increment summation method, after recognition of the cohorts. Production was in general lower in the Mondego estuary when compared to other systems, which was associated to the estuary's small area (only 3.4 km2, less than 1/4 of area compared to other studied systems). Dicentrarchus labrax was among the most productive species. Production decreased in the drought year for all species, especially evident for D. labrax, P. minutus and P. flesus. No direct effects could be attributable to the salinity and temperature variations and to the low freshwater discharges (resulting from the drought and high temperatures), yet these were pointed as probable major reasons for the decreased production. A significant reduction (15-45% reduction in the estuarine production) was also concluded for the potential production to be exported for coastal areas by the nursery species in the drought conditions.http://www.sciencedirect.com/science/article/B6WDV-4R9GGXS-2/1/663d5981f8928a75fea6999bf328f16

    Contribution of primary producers to mercury trophic transfer in estuarine ecosystems: Possible effects of eutrophication

    Get PDF
    http://www.sciencedirect.com/science/article/B6V6N-4V2X6WR-2/2/583d9d39ab618163fcc19f359dde856

    Penyisipan Gen Inhibitor α-Amilase Pada Plasmid Biner PCambia 1301

    Full text link
    The experiment was conducted at the Molecular Biology Laboratory of the Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development, Bogor. The objective was to construct -ai gene on a binary plasmid pCambia 1301. This experiment was carried out using construction method by ligation process between fragments of α-ai gene from pTA3 plasmid and pCambia 1301 on HindIII site. The result of ligant transformation into E. coli DH5α was 182 surviving colonies on YEP medium containing kanamycin. DNA samples were obtained from 60 randomly selected colonies. The restriction pattern was tested by digesting each DNA sample using HindIII showed colonies containing two fragments expected of sizes wich are 11.837 and 4.887 kb. Two colonies are predicted containing of α-ai gene on its the binary plasmid. Advanced tests using restriction enzymes BamHI and XbaI showed two directions (right and left) of α-ai gene. The right direction was shown by pCambia-α-ai1 from colony number 43. This plasmid showed expected fragments of sizes 13.485 and 3.219 kb when digested with BamHI and two fragments of sizes 15.421 and 1.303 kb when digested with XbaI. The left direction was shown pCambia-α-ai2 from colony number 58. This plasmid also demon-strated expected fragments of sizes 15.026 and 1.698 kb when digested with BamHI and two fragments of sizes 13.082 and 3.642 kb when digested with XbaI. Both pCambia-α-ai1 and pCambia-α-ai2 were transformed into A. tumefaciens LBA4404
    corecore