More than symbioses : orchid ecology ; with examples from the Sydney Region

The Orchidaceae are one of the largest and most diverse families of flowering plants. Orchids grow as terrestrial, lithophytic, epiphytic or climbing herbs but most orchids native to the Sydney Region can be placed in one of two categories. The first consists of terrestrial, deciduous plants that live in fire-prone environments, die back seasonally to dormant underground root tubers, possess exclusively subterranean roots, which die off as the plants become dormant, and belong to the subfamily Orchidoideae. The second consists of epiphytic or lithophytic, evergreen plants that live in fire-free environments, either lack specialised storage structures or possess succulent stems or leaves that are unprotected from fire, possess aerial roots that grow over the surface of, or free of, the substrate, and which do not die off seasonally, and belong to the subfamily Epidendroideae. Orchid seeds are numerous and tiny, lacking cotyledons and endosperm and containing minimal nutrient reserves. Although the seeds of some species can commence germination on their own, all rely on infection by mycorrhizal fungi, which may be species-specific, to grow beyond the earliest stages of development. Many epidendroid orchids are viable from an early stage without their mycorrhizal fungi but most orchidoid orchids rely, at least to some extent, on their mycorrhizal fungi throughout their lives. Some are completely parasitic on their fungi and have lost the ability to photosynthesize. Some orchids parasitize highly pathogenic mycorrhizal fungi and are thus indirectly parasitic on other plants. Most orchids have specialised relationships with pollinating animals, with many species each pollinated by only one species of insect. Deceptive pollination systems, in which the plants provide no tangible reward to their pollinators, are common in the Orchidaceae. The most common form of deceit is food mimicry, while at least a few taxa mimic insect brood sites. At least six lineages of Australian orchids have independently evolved sexual deception. In this syndrome, a flower mimics the female of the pollinating insect species. Male insects are attracted to the flower and attempt to mate with it, and pollinate it in the process. Little is known of most aspects of the population ecology of orchids native to the Sydney Region, especially their responses to fire. Such knowledge would be very useful in informing decisions in wildlife management

Viscous vortex flows

Several computational studies are currently being pursued that focus on various aspects of representing the entire lifetime of the viscous trailing vortex wakes generated by an aircraft. The formulation and subsequent near-wing development of the leading-edge vortices formed by a delta wing are being calculated at modest Reynolds numbers using a three-dimensional, time-dependent Navier-Stokes code. Another computational code was developed to focus on the roll-up, trajectory, and mutual interaction of trailing vortices further downstream from the wing using a two-dimensional, time-dependent, Navier-Stokes algorithm. To investigate the effect of a cross-wind ground shear flow on the drift and decay of the far-field trailing vortices, a code was developed that employs Euler equations along with matched asymptotic solutions for the decaying vortex filaments. And finally, to simulate the conditions far down stream after the onset of the Crow instability in the vortex wake, a full three-dimensional, time-dependent Navier-Stokes code was developed to study the behavior of interacting vortex rings

The systematics and biogeography of the Persooniinae (Proteaceae)

Tese de mestrado em Geografia Humana - Ordenamento do Território e Desenvolvimento, apresentada para o Departamento de Geografia da Faculdade de Letras da Universidade de CoimbraA geografia, através de suas variadas correntes críticas busca elucidar as contradições contemporâneas e históricas do espaço urbano. Estes enfoques são bastante incisivos no que diz respeito à atual dinâmica global e suas consequências em diversas escalas, sobretudo na relação local – global, dos espaços urbanos e seus movimentos de (re)produção do espaço. Tais relações são materializadas através de políticas e tratados propostos por instituições globais, universidades e empresas que operam a nível global e são na maioria dos casos, organizações sediadas ao Norte Global. Esta enunciação de determinado conhecimento através destas relações globais de poder, se apresentam enquanto assimétricas desde o surgimento do sistema mundo moderno-colonial, e são transpostos para realidades distantes dos lugares de suas formulações e esta (re)territorialização de capitais e outros fluxos, incidem de maneira vertical e avassaladora em diversos territórios, neste caso, nas cidades do Sul Global, exemplo do Rio de Janeiro. São justamente as contradições coloniais, as primeiras à aferirem ao Rio de Janeiro, um espaço urbano desigual à partir de subjugos e subordinações de outros territórios. Atualmente, estas subordinações de determinados territórios por parte de núcleos urbanos, são legitimadas através de planejamentos urbanos que buscam adequar-se as condições de produção flexíveis, surgida à partir das tecnologias de informação e comunicação no decorrer da segunda metade do século XX. Estes planejamentos, intitulados estratégicos, são fruto de estudos voltados para ambientes empresariais, de gestões que visam superávits. Ao transpormos uma visão empresarial à gestão pública urbana, como a prefeitura do Rio de Janeiro, suas consequências serão a continuidade dos processos desiguais acima citados. As desigualdades serão ainda mais latentes e visíveis, através da construção de muros, do impedimento de certos grupos de moverem-se pela cidade, a segregação de áreas, ou ainda como no caso da apropriação pejorativa e ideológica da categoria do subúrbio carioca. O planejamento estratégico aliado ao rapto ideológico da categoria de subúrbio, ampliados pelas contradições coloniais (raciais) e da colonialidade nos revelam que estes territórios permanecerão sendo tratados de maneira secundária e subordinada e suas populações em busca da sobrevivência e algum reconhecimento. Porém, a utopia e as buscas por esta sobrevivência e reconhecimento sempre farão parte destes subúrbios. Territórios precarizados, mas repleto de inovações e movimentos variados que vão em busca de um desenvolvimento local. Considerando a mobilidade urbana enquanto parte estrutural do urbano e um dos pilares do desenvolvimento local, uma proposta inovadora é construída através de relações horizontais, vai ser a frente de batalha para o (re)surgimento de subúrbios transformados por dentro, sem que as relações em escalas globais se percam, mas que sejam estas, subordinas as decisões e anseios locais. Um módulo de Veículo Leve sobre Trilhos e sua territorialização simbólica e material para determinada porção do subúrbio do Rio de Janeiro é o eixo de organização entre a sociedade civil organizada, esta pesquisa e as possibilidades de luta e conquista de utopias.Geography, through its various critical currents seeks to elucidate the contemporary and historical contradictions of urban space. These approaches are very incisive with regard to the current global dynamics and their consequences at various scales, particularly in the local connection - global, urban spaces and movements of (re) production of space. Such relationships are materialized through policies and treaties proposed by global institutions, universities and companies that operate globally and are in most cases based organizations to the Global North. This enumeration of certain knowledge through these global power relations, are presented as asymmetrical since the emergence of the modern-colonial world system, and are translated into distant realities of the places of their formulations and this repossession capital and other flows, focus vertical way and overwhelming in different territories, in this case, in the cities of the Global South, example of Rio de Janeiro. It is precisely the colonial contradictions, the first to aferirem to Rio de Janeiro, uneven urban space starting at overwhelm and subordination of other territories. Currently, these subordination of certain territories by urban centers, are legitimized through urban planning that seek to adapt to flexible production conditions, arising from the information and communication technologies during the second half of the twentieth century. These plans, strategic entitled, are the result of studies into enterprise environments, the efforts aimed surpluses. Transpormos to a corporate vision of urban governance, as the mayor of Rio de Janeiro, its consequences will be the continuation of unequal cases cited above. Inequalities will be even more latent and visible, by building walls, the prevention of certain groups to move around the city, segregation of areas, or as in the case of pejorative and ideological appropriation category of Rio suburbs. Strategic planning combined with ideological abduction of suburban category, magnified by the colonial contradictions (racial) and coloniality tell us that these territories remain being treated for secondary and subordinate way and their populations in search of survival and some recognition. But the utopia and the search for survival and this recognition will always be part of these suburbs. Precarious territories, but full of innovations and varied movements that go in search of a local development. Considering urban mobility as a structural part of the city and one of the pillars of local development, an innovative proposal is built through horizontal relations, will be the front line for the (re) emergence of suburbs transformed from within, without relations in global scales should perish, but that these are, subordinas decisions and local aspirations. A vehicle module Light Rail and its symbolic territorial and material for particular portion of the suburb of Rio de Janeiro is the organization of axis between organized civil society, this research and the possibilities of struggle and achievement of utopias

The impact of distance and a shifting temperature gradient on genetic connectivity across a heterogeneous landscape

<p>Abstract</p> <p>Background</p> <p>Inter-population distance and differences in breeding times are barriers to reproduction that can contribute to genotypic differentiation between populations. Temporal changes in environmental conditions and local selective processes can further contribute to the establishment of reproductive barriers. <it>Telopea speciosissima </it>(Proteaceae) is an excellent subject for studying the effect of geographic, edaphic and phenological heterogeneity on genotypic differentiation because previous studies show that these factors are correlated with morphological variation. Molecular, morphological and environmental datasets were combined to characterise the relative influence of these factors on inter-population differentiation, and Bayesian analyses were used to investigate current levels of admixture between differentiated genomes.</p> <p>Results</p> <p>A landscape genetic approach involving molecular and morphological analyses identified three endpoints of differentiated population groups: coastal, upland and southern. The southern populations, isolated from the other populations by an edaphic barrier, show low migration and no evidence of admixture with other populations. Amongst the northern populations, coastal and upland populations are connected along a skewed altitudinal gradient by genetically intermediate populations. The strong association between temperature and flowering time in <it>Telopea speciosissima </it>was shown to maintain a temporally unstable reproductive barrier between coastal and upland populations.</p> <p>Conclusions</p> <p>Substrate-mediated allopatry appears to be responsible for long-term genetic isolation of the southern populations. However, the temperature-dependent reproductive barrier between upland and coastal populations bears the genetic signature of temporal adjustments. The extreme climatic events of the last glacial maximum are likely to have caused more complete allochronic isolation between upland and coastal populations, as well as exerting increased selective pressure upon local genomes. However, at intermediate altitudes, current climatic conditions allow for the incorporation of alleles from previously distinct genomes, generating new, intermediate genomic assemblages and possibly increasing overall adaptive potential.</p

The taxonomy, ecology and biology of the 'Banksia spinulosa' SM. complex (Proteaceae)

The 'Banksia spinulosa' complex ranges from Mossman in north Queensland down the east coast of Australia to Wilsons Promontory in Victoria, with four isolated populations in central Queensland. A morphometric analysis (SSH-MDS ordination and UPGMA clustering) of individuals for 34 characters and 234 specimens from mature plants collected across the full geographic and morphological range of the 'B. spinulosa' complex supports the recognition of 'Banksia vincentia' (Chapter 2), the recognition of the four other named entities ('B. neoanglica', 'B. spinulosa', 'B. collina sens. str.', 'B. cunninghamii'), and of 12 putative entities, viz. B. Julatten, B. Mount Mee, B. Tewantin, B. McPherson Range, B. Kungala, B. Putty Road, B. Carnarvon Gorge, B. Robinson Gorge, B. Isla Gorge, B. Cockatoo, B. Croajingolong, B. Wilsons Promontory (Chapter 3). The results in chapters 2–3 are considered and discussed in the context of competing species concepts. The integrated species concept of De Queiroz is favoured and informs the need for the study undertaken on seedling morphology (Chapter 4). Examination of seedling morphology illustrates the importance of looking at both adult and seedling morphology when delimiting species. While most entities in the 'B. spinulosa' complex are heteroblastic several are homoblastic. Aside from these developmental changes, leaf morphology is relatively fixed for entities in the 'B. spinulosa' complex regardless of biotic or abiotic influences (Chapter 4)

Molecular differentiation of the Murraya paniculata Complex (Rutaceae: Aurantioideae: Aurantieae)

Background: Orange jasmine has a complex nomenclatural history and is now known as Murraya paniculata (L.) Jack. Our interest in this common ornamental stemmed from the need to resolve its identity and the identities of closely related taxa as hosts of the pathogen 'Candidatus Liberibacter asiaticus' and its vector Diaphorina citri. Understanding these microbe-vector-plant relationships has been hampered by taxonomic confusion surrounding Murraya at both the generic and specific levels. Results: To resolve the taxonomic uncertainty, six regions of the maternally-inherited chloroplastal genome and part of the nuclear-encoded ITS region were amplified from 85 accessions of Murraya and Merrillia using the polymerase chain reaction (PCR). Clustering used maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI). Chronograms were produced for molecular dating, and to test the monophyly of Murraya rigorously, using selected accessions of Murraya and 26 accessions of the Rutaceae and Simarubaceae. Sequence data from the ITS and chloroplastal regions suggest that Murraya paniculata (sensu (Swingle WT and Reece CR, The Citrus Industry, p. 190-430, 1967)) can be separated into four distinct but morphologically somewhat cryptic taxa: Murraya paniculata (sensu (Mabberley DJ, Taxon 65:366-371, 2016)), M. elongata, M. sumatrana and M. lucida. In addition, Murraya omphalocarpa was identified as a putative hybrid of M. paniculata and M. lucida with two geographically isolated nothovarieties representing reciprocal crosses. Murraya is monophyletic, and molecular dating suggests that it diverged from Merrillia during the Miocene (23-5 Ma) with this Murraya group speciating and dispersing during the Middle Miocene onwards. Conclusions: The accessions from Asia and Australasia used in this study grouped into biogeographical regions that match herbarium specimen records for the taxa that suggest natural allopatric distributions with limited overlap and hybridity. Murraya paniculata has been distributed around the world as an ornamental plant. The division of the Murraya paniculata complex into four species with a rare hybrid also confirms morphological studies

APOBEC mutagenesis is a common process in normal human small intestine

APOBEC mutational signatures SBS2 and SBS13 are common in many human cancer types. However, there is an incomplete understanding of its stimulus, when it occurs in the progression from normal to cancer cell and the APOBEC enzymes responsible. Here we whole-genome sequenced 342 microdissected normal epithelial crypts from the small intestines of 39 individuals and found that SBS2/SBS13 mutations were present in 17% of crypts, more frequent than most other normal tissues. Crypts with SBS2/SBS13 often had immediate crypt neighbors without SBS2/SBS13, suggesting that the underlying cause of SBS2/SBS13 is cell-intrinsic. APOBEC mutagenesis occurred in an episodic manner throughout the human lifespan, including in young children. APOBEC1 mRNA levels were very high in the small intestine epithelium, but low in the large intestine epithelium and other tissues. The results suggest that the high levels of SBS2/SBS13 in the small intestine are collateral damage from APOBEC1 fulfilling its physiological function of editing APOB mRNA. Whole-genome sequencing of healthy human epithelial crypts from the small intestines of 39 individuals highlights APOBEC enzymes as a common contributor to the overall mutational burden in this tissue.Peer reviewe

Testing foundations of quantum mechanics with photons

The foundational ideas of quantum mechanics continue to give rise to counterintuitive theories and physical effects that are in conflict with a classical description of Nature. Experiments with light at the single photon level have historically been at the forefront of tests of fundamental quantum theory and new developments in photonics engineering continue to enable new experiments. Here we review recent photonic experiments to test two foundational themes in quantum mechanics: wave-particle duality, central to recent complementarity and delayed-choice experiments; and Bell nonlocality where recent theoretical and technological advances have allowed all controversial loopholes to be separately addressed in different photonics experiments.Comment: 10 pages, 5 figures, published as a Nature Physics Insight review articl