Stimulate® na micropropagação da mandioca (Manihot esculenta Crantz).

A cultura de ápices caulinares, que consiste na utilização do meristema apical como explante de partida para a micropropagação de plantas livres de doenças, é a técnica de cultivo in vitro mais utilizada em mandioca. O processo de micropropagação pode ser influenciado por fatores externos, como temperatura, umidade relativa, fotoperíodo, intensidade luminosa, e fatores intrínsecos ao crescimento e desenvolvimento vegetativo, dependentes de fatores como genótipo, tipos e tamanhos de explantes, além das condições nutricionais do meio de cultivo e da aplicação de fitorreguladores

Redes pedonais para pessoas com mobilidade reduzida : exercício de avaliação multicritério em Braga, Portugal

A mobilidade urbana é um fator primordial para os planeadores urbanos e decisores no desenvolver da sua atividade, principalmente quando esta tem como objeto as viagens da população com mobilidade reduzida. No âmbito da realidade portuguesa, o presente trabalho avaliou se as características físicas de um determinado espaço urbano respeitam as exigências do Decreto-Lei 163/2006. Neste enquadramento foi idealizado um modelo de avaliação multicritério do grau de conformidade dos espaços. De acordo com as normas vigentes foi gerada uma classificação dos locais estudados. Este modelo integra a normalização das medições efetuadas para os itens considerados e a sua agregação, gerando um índice que exprime o grau de conformidade do local avaliado. O modelo foi implementado em ambiente SIG para permitir a representação dos resultados alcançados em mapas e aplicado a um caso de estudo na cidade de Braga, Portugal.Mobility is pointed as a key issue to urban planners and managers, especially when dealing with the mobility of pedestrians with mobility constraints. The goal of the present work is to analyze factors that limit the circulation of people with mobility constraints and to map those conditions in central urban spaces. Taking into account only the physical characteristics of urban spaces, the assessment is performed in agreement with the standards specified in the Portuguese Law. A multi-criteria model was developed to evaluate the compliance of urban spaces with those standards. Its integration within a GIS platform was performed, enabling a spatial analysis of the results. A case study was conducted in a central area of the city of Braga, Portugal. Maps showing levels of compliance with the standards were produced and the results were discussed

Pedestrian mobility : mapping circulation conditions for people with mobility constraints in a central urban area

Nowadays, pedestrian mobility is regarded as a key issue to urban planners since several studies have pointed it as an influential factor to the quality of life in central city areas. Consequently, walking conditions must be evaluated and some measures should be taken whenever the results show inappropriate implementations. This concern increases when focusing on the movement of people with mobility constraints, because for them a physical obstacle can represent an insurmountable obstruction. The goal of the present work is to analyze factors that limit the circulation of people with mobility constraints and to map those conditions in central urban areas. Taking into account only the physical characteristics of urban spaces, the assessment is performed in agreement with the standards specified in the Portuguese Law, defined by Decree-Law Nr 163/2006, in short DL 163/2006. The first part of the work introduces a multi-criteria model developed to evaluate the compliance of urban spaces with those standards. This model defines the normalization of measured values for each considered criterion, as well as their aggregation to achieve an index that expresses the compliance level of the evaluated urban spaces. The integration of the model within a GIS platform was performed in order to implement a spatial analysis of the results. The second part shows and discusses the results of a case study in a central area of the city of Braga, Portugal. The chosen area allows for the analysis of sidewalks and crosswalks of streets as a continuous network. Some sidewalk segments constructed before the approval of this law were also included allowing a comparative analysis with new (or improved) segments. The map of results highlights the sidewalk segments with worst performance, reflecting lower index values. This map is very helpful to city managers when identifying critical areas that require an intervention in order to improve the mobility of those pedestrians. Moreover, the proposed model can be easily adapted for other cities and countries

Plagioclase and biotite compositions tracing granite genesis and evolution: insights from two syntectonic granitoids from Aguiar da Beira (N Portugal)

The Aguiar da Beira area (N Portugal) is located within the Central-Iberian Zone (CIZ) of the Iberian Variscan Belt. It is mainly composed by granitoids emplaced during (syntectonic) or slightly after (late- to post-tectonic) the last ductile deformation event of the Variscan orogeny (D3). From the petrological and geochemical point of view, the syntectonic granitoids from the CIZ can be included into two genetically distinct suites: (a) calc-alkaline granodiorites and biotite granites, and (b) strongly peraluminous leucogranites and two-mica granites. In the Aguiar da Beira area, the first group is represented by a small intrusion of a medium- to coarse-grained porphyritc biotite granodiorite-granite, emplaced 322 Ma ago, characterized by a slightly peraluminous and moderately evolved composition. The second group comprises a NW-SE elongated pluton of a strongly peraluminous and highly evolved medium- to fine-grained muscovite-biotite granite (317 Ma), showing occasionally a gneissic foliation concordant with the D3 variscan structures. Based on geochemical and Sr-Nd and 18O isotopic data, the biotite granodiorite-granite melt is interpreted either as the result of partial melting of heterogeneous lower crustal materials, or as the product of mixing of mantle derived magmas and lower crustal felsic anatectic melts. In contrast, the muscovite-biotite gneissic granite magma appears to have been exclusively generated by partial melting of upper crustal metasediments and suffered a subsequent evolution dominantly controlled by fractional crystallization processes. Plagioclase and biotite major and trace element compositions can be used to constrain the origin and evolution of the two granitoids and provide strong evidence in support of the proposed petrogenetic models. In the biotite granodiorite-granite, the plagioclase is characterized by a wide compositional range (An20-33), high Sr (749 – 869 ppm) and Ba (32 – 351 ppm) contents and a Sr discontinuous zonation pattern, whilst the biotite shows high TiO2 (2.92 – 3.30 wt%), Ba (407 – 589 ppm), V (214 – 234 ppm), and low Al2O3 (16.83 – 18.03 wt%), Li (335 – 367 ppm), Zn (262 – 279 ppm) and Fet/(Fet + Mg) (0.54 – 0.55) contents. These data confirm the typical calc-alkaline affinity of this intrusion and reveal that these phase minerals crystallized under disequilibrium conditions. In contrast, the plagioclase from the muscovite-biotite granite displays a narrower compositional range (An1-7), unzoned or normally zoned compositional patterns and lower Sr (19 – 33 ppm) and Ba (1.1 – 2.0 ppm) contents, reflecting the highly evolved character of this intrusion and near equilibrium crystallization conditions. The biotite crystals from the muscovite-biotite granite plot in the field of the alumino-potassic series in the AlVI versus Mg diagram (Nachit et al., 1983), supporting a major contribution of metasedimentary rocks for the genesis of this magma. Their AlVI contents increase with decreasing Mg suggesting an important role for fractional crystallization processes during magmatic evolution. The range of AlVI and Fet/(Fet + Mg) values (AlVI: 0.482 – 0.487; Fet/(Fet + Mg): 0.72 – 0.83) displayed by the biotites show that the muscovite-biotite granite crystallized from a reduced magma (low O2), which is consistent with its inferred sedimentary provenance

Fine-scale genetic breaks driven by historical rangedynamics and ongoing density-barrier effects in theestuarine seaweed Fucus ceranoides L.

Factors promoting the emergence of sharp phylogeographic breaks include restricted dispersal, habitat discontinuity, physical barriers, disruptive selection, mating incompatibility, genetic surfing and secondary contact. Disentangling the role of each in any particular system can be difficult, especially when species are evenly distributed across transition zones and dispersal barriers are not evident. The estuarine seaweed Fucus ceranoides provides a good example of highly differentiated populations along its most persistent distributional range at the present rear edge of the species distribution, in NW Iberia. Intrinsic dispersal restrictions are obvious in this species, but have not prevented F. ceranoides from vastly expanding its range northwards following the last glaciation, implying that additional factors are responsible for the lack of connectivity between neighbouring southern populations. In this study we analyze 22 consecutive populations of F. ceranoides along NW Iberia to investigate the processes generating and maintaining the observed high levels of regional genetic divergence. Results Variation at seven microsatellite loci and at mtDNA spacer sequences was concordant in revealing that Iberian F. ceranoides is composed of three divergent genetic clusters displaying nearly disjunct geographical distributions. Structure and AFC analyses detected two populations with an admixed nuclear background. Haplotypic diversity was high in the W sector and very low in the N sector. Within each genetic cluster, population structure was also pervasive, although shallower. Conclusions The deep divergence between sectors coupled with the lack of support for a role of oceanographic barriers in defining the location of breaks suggested 1) that the parapatric genetic sectors result from the regional reassembly of formerly vicariant sub-populations, and 2) that the genetic discontinuities at secondary contact zones (and elsewhere) are maintained despite normal migration rates. We conclude that colonization and immigration, as sources of gene-flow, have very different genetic effects. Migration between established populations is effectively too low to prevent their differentiation by drift or to smooth historical differences inherited from the colonization process. F. ceranoides, but possibly low-dispersal species in general, appear to be unified to a large extent by historical, non-equilibrium processes of extinction and colonization, rather than by contemporary patterns of gene flow.Peer Reviewe

A multicriteria model for evaluating conformity of travelling conditions for pedestrians with mobility constraints

For people with mobility constraints, the conditions offered by pedestrian environments are crucial for their ability to remain independent and self-sufficient. Mobility is also a key factor to maintain people actively involved in the community. Taking into account only the physical characteristics of urban spaces, the goal of the present work is to analyse the factors that limit the circulation of people with mobility constraints and to map those conditions in central urban spaces. The assessment was performed in agreement with the standards specified in the Portuguese Law. A multi-criteria model was developed to evaluate the compliance of urban spaces with those standards. Its integration within a GIS platform was performed in order to implement a spatial analysis of the results. A case study was conducted in a central area of the city of Braga, Portugal. Maps showing levels of compliance with the standards were produced and the results are discussed.(undefined

Circulation environment in urban spaces for pedestrians with mobility constraints : a case study in Braga, Portugal

Mobility is pointed as a key issue to urban planners and managers. In particular the case of pedestrians with mobility constraints implies considering specific parameters. The goal of the present work is to analyse factors that limit the circulation of people with mobility constraints and to map those conditions in central urban spaces. Taking into account only the physical characteristics of urban spaces, the assessment is performed in agreement with the standards specified in the Portuguese Law. A multi-criteria model was developed to evaluate the compliance of urban spaces with those standards. Its integration within a GIS platform was performed in order to implement a spatial analysis of the results. A case study was conducted in a central area of the city of Braga, Portugal. Maps showing levels of compliance with the standards were produced and the results were discussed