17 research outputs found

    Weda, a new genus with two new species of Euphorbiaceae‐Crotonoideae from Halmahera (North Maluku, Indonesia) and phylogenetic relationships of the Australasian tribe Ricinocarpeae

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    During the environmental impact study for a proposed nickel mine near Weda Bay on Halmahera in North Moluccas (Maluku Utara Province), Indonesia, two unknown Euphorbiaceae were discovered. Morphological comparisons and molecular phylogenetic analyses using four markers (plastid trnL-F and rbcL, and nuclear ribosomal internal transcribed spacer and external transcribed spacer) indicated that they should be recognized as constituting a new, distinct genus of two species, which are described and illustrated here as Weda fragarioides and Weda lutea. The new taxa are members of the Australasian tribe Ricinocarpeae in subfamily Crotonoideae, and they are most closely related to Alphandia. In contrast with the otherwise mostly sclerophyllous Ricinocarpeae, Weda possesses stellate to dendritic hairs, large, long-petiolate, glandular leaves, and inflorescences with a pair of large, leafy, subopposite bracts. The two narrowly distributed species are distinguished from each other by vegetative and floral features, molecular data, and elevational preferences. Leaf elemental analysis of Weda indicated manganese, but not nickel, accumulation. Newly resolved generic relationships and potential morphological synapomorphies within Crotonoideae are discussed, and the circumscription of Ricinocarpeae is expanded from 7 to 11 genera.NaturalisPlant science

    Spontaneous formation of flux concentrations in a stratified layer

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    The negative effective magnetic pressure instability discovered recently in direct numerical simulations (DNS) may play a crucial role in the formation of sunspots and active regions in the Sun and stars. This instability is caused by a negative contribution of turbulence to the effective mean Lorentz force (the sum of turbulent and non-turbulent contributions) and results in formation of large-scale inhomogeneous magnetic structures from initial uniform magnetic field. Earlier investigations of this instability in DNS of stably stratified, externally forced, isothermal hydromagnetic turbulence in the regime of large plasma beta are now extended into the regime of larger scale separation ratios where the number of turbulent eddies in the computational domain is about 30. Strong spontaneous formation of large-scale magnetic structures is seen even without performing any spatial averaging. These structures encompass many turbulent eddies. The characteristic time of the instability is comparable to the turbulent diffusion time, L^2/eta_t, where eta_t is the turbulent diffusivity and L is the scale of the domain. DNS are used to confirm that the effective magnetic pressure does indeed become negative for magnetic field strengths below the equipartition field. The dependence of the effective magnetic pressure on the field strength is characterized by fit parameters that seem to show convergence for larger values of the magnetic Reynolds number.Comment: 14 pages, 8 figures, submitted to special issue "Advances of European Solar Physics" in Solar Physic

    Local knowledge of medicinal plants in three artisanal fishing communities (Itapoá, Southern Brazil), according to gender, age, and urbanization Conhecimento local sobre plantas medicinais em três comunidades de pescadores artesanais (Itapoá, sul do Brasil), de acordo com gênero, idade e urbanização

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    This article analyzes some of the factors affecting the distribution of knowledge about medicinal plants of three artisanal fishing communities in Itapoá Municipality, in the state of Santa Catarina, Brazil. Ninety semi-structured interviews were performed, which resulted in 109 cited plant species. The sample included both men (n=46) and women (n=44), in different age categories: 18-40 years old (n=18), 41-50 (n=21), 51-60 (n=28), and 61+ years old (n=23), and in three different communities: Barra do Saí (n=17), Itapema do Norte (n=31) and Pontal do Norte (n=42). Leaves are the plant parts most used by the communities (62%), and are obtained primarily through cultivation. Cordia curassavica (Jacq.) Roem. & Schult. (Boraginaceae) is the species most cited in the interviews, locally known as 'erva-baleeira' or 'erva-de-baleia'. The elderly have greater knowledge of species, but no gender differences were noticed. Less knowledge of plants was noticed in the more urbanized area when compared to the less urbanized areas. The most used plants are not related to the most frequent ailments. Medicinal plant use is an important resource for the health of these fishing communities, but it is declining mostly due to the lack of interest on the part of the younger members, and to improved access to public health services.<br>Este artigo analisa alguns dos fatores que afetam a distribuição do conhecimento sobre plantas medicinais em três comunidades de pescadores artesanais do Município de Itapoá, Santa Catarina, Brasil. Noventa entrevistas semi-estruturadas foram realizadas, o que resultou em 109 espécies de plantas citadas. A amostra foi composta por homens (n = 46) e mulheres (n = 44), em diferentes categorias de idade: 18-40 anos (n = 18), 41-50 (n = 21), 51-60 (n = 28), e 61 anos ou mais (n = 23), e em três diferentes comunidades: Barra do Saí (n = 17), Itapema do Norte (n = 31) e Pontal do Norte (n = 42). Folhas são as partes da plantas mais utilizadas (62%), sendo obtidas principalmente por cultivo. Cordia curassavica (Jacq.) Roem. & Schult. (Boraginaceae) é a espécie mais citada nas entrevistas, localmente chamada de "erva-baleeira" ou "erva-de-baleia". Os idosos têm um maior conhecimento sobre as espécies, mas não houve diferenças em relação ao sexo dos entrevistados. Um menor conhecimento sobre as plantas foi observado na área mais urbanizada, quando comparada com as áreas menos urbanizadas. As plantas mais utilizadas não estão relacionadas com as doenças mais freqüentes. As plantas medicinais são um recurso importante para a saúde dessas comunidades de pescadores, mas este conhecimento pode estar se deteriorando devido principalmente à falta de interesse dos membros mais jovens e à melhoria do acesso aos serviços públicos de saúde

    An evaluation of the role and impacts of alien finfish in Asian inland aquaculture

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    Asia dominates global aquaculture production accounting for over 80% of the total and the mainstay in Asian aquaculture is finfish. Over the years, Asia has experienced a number of inter-continental and intra-continental transfers/introductions/translocation of finfish species, between nations and watersheds, beyond their natural range of distribution, primarily for aquaculture development. In this article all such species are referred to as alien species. An attempt is made to evaluate the importance of the production of alien species in selected Asian nations, using statistics of the Food and Agriculture Organization. Also, negative effects, if any, based on literature surveys, of alien species in relation to displacement of indigenous species, and on biodiversity and/or genetic diversity together with associated pathogen transfers are evaluated. The major alien species, based on their significance to Asian inland aquaculture considered, are the tilapias, catfish, Chinese and Indian major carps and common carp. It is estimated that currently alien species account for nearly 12% of the cultured finfish production (2.6 million tonnes) in Asia, valued at US$ 2.59 billion, and the contribution exceeds 40% when Asian countries excluding China are taken into consideration. Inland finfish aquaculture in some Asian nations, such as Indonesia and the Philippines, is predominated by alien species, and in some others, e.g. Bangladesh and India, the contribution from alien species has been increasing steadily. It is suggested that overall alien finfish species have done little ecological harm to native flora and fauna. However, in the wake of increasing anthropogenic development taking place in watersheds the resulting environments are often made unconducive to indigenous species but not to some alien species, thereby potentially and indirectly making the latter invasive.<br /

    Solar Dynamics, Rotation, Convection and Overshoot

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