An analysis of major target deviations in craniospinal irradiation treatment plans for patients with intermediate-risk medulloblastoma within a phase 3 clinical trial (Children\u27s Oncology Group Study ACNS0331)

PURPOSE: Craniospinal irradiation remains an essential and yet difficult part of the treatment of patients with medulloblastoma. Whereas technological advances offer promise of increased conformity, realiance on advanced technology is not without risk, and it remains critical to carefully delineate targets. We describe examples of target deviations (TDs) in craniospinal irradiation treatment plans for postoperative patients with medulloblastoma in a phase 3 clinical trial (ACNS 0331). METHODS AND MATERIALS: The principal investigator independently performed a review of the treatment plans and portal films of enrolled patients and evaluated the plans for TDs. TDs of dose, dose uniformity, and volume were defined as major or minor deviations. Major TDs scored as protocol violations. The effect of major TDs on event-free survival (EFS) and overall survival (OS) was evaluated using the stratified Cox proportional hazards model. RESULTS: Of the 549 patients enrolled, 461 were available for this analysis. Thirty-two (7%) plans did not have data sufficient for TD evaluation. Major TDs were found in 32 of the 461 plans (7%). Of those, 21 were deviations of target volume alone, 7 were deviations of target dose alone, and 4 were deviations of both target volume and dose. The 25 patients with TDs of volume involved 29 sites. The most common major TDs of volume involved the brain (9 of 29) and the posterior fossa (9 of 29). On Cox proportional hazards modeling, the presence of a major TD did not statistically significantly affect EFS (hazard ratio, 0.98; 95% confidence interval, 0.45-2.11; CONCLUSIONS: Although intensity modulated radiation therapy and proton therapy are promising in improving conformity and sparing organs at risk, technology does not substitute for careful anatomic definition of target volumes. The study was not powered to evaluate the effect of TDs on EFS and OS; therefore, the statistical analysis presented in this study must be interpreted with caution

Modelling Human-Fire Interactions: Combining Alternative Perspectives and Approaches

Although it has long been recognised that human activities affect fire regimes, the interactions between humans and fire are complex, imperfectly understood, constantly evolving, and lacking any kind of integrative global framework. Many different approaches are used to study human-fire interactions, but in general they have arisen in different disciplinary contexts to address highly specific questions. Models of human-fire interactions range from conceptual local models to numerical global models. However, given that each type of model is highly selective about which aspects of human-fire interactions to include, the insights gained from these models are often limited and contradictory, which can make them a poor basis for developing fire-related policy and management practices. Here, we first review different approaches to modelling human-fire interactions and then discuss ways in which these different approaches could be synthesised to provide a more holistic approach to understanding human-fire interactions. We argue that the theory underpinning many types of models was developed using only limited amounts of data and that, in an increasingly data-rich world, it is important to re-examine model assumptions in a more systematic way. All of the models are designed to have practical outcomes but are necessarily simplifications of reality and as a result of differences in focus, scale and complexity, frequently yield radically different assessments of what might happen. We argue that it should be possible to combine the strengths and benefits of different types of model through enchaining the different models, for example from global down to local scales or vice versa. There are also opportunities for explicit coupling of different kinds of model, for example including agent-based representation of human actions in a global fire model. Finally, we stress the need for co-production of models to ensure that the resulting products serve the widest possible community

Modelling human-fire interactions: combining alternative perspectives and approaches

Although it has long been recognised that human activities affect fire regimes, the interactions between humans and fire are complex, imperfectly understood, constantly evolving, and lacking any kind of integrative global framework. Many different approaches are used to study human-fire interactions, but in general they have arisen in different disciplinary contexts to address highly specific questions. Models of human-fire interactions range from conceptual local models to numerical global models. However, given that each type of model is highly selective about which aspects of human-fire interactions to include, the insights gained from these models are often limited and contradictory, which can make them a poor basis for developing fire-related policy and management practices. Here, we first review different approaches to modelling human-fire interactions and then discuss ways in which these different approaches could be synthesised to provide a more holistic approach to understanding human-fire interactions. We argue that the theory underpinning many types of models was developed using only limited amounts of data and that, in an increasingly data-rich world, it is important to re-examine model assumptions in a more systematic way. All of the models are designed to have practical outcomes but are necessarily simplifications of reality and as a result of differences in focus, scale and complexity, frequently yield radically different assessments of what might happen. We argue that it should be possible to combine the strengths and benefits of different types of model through enchaining the different models, for example from global down to local scales or vice versa. There are also opportunities for explicit coupling of different kinds of model, for example including agent-based representation of human actions in a global fire model. Finally, we stress the need for co-production of models to ensure that the resulting products serve the widest possible community

Australia: A Continent Without Native Powdery Mildews? The First Comprehensive Catalog Indicates Recent Introductions and Multiple Host Range Expansion Events, and Leads to the Re-discovery of Salmonomyces as a New Lineage of the Erysiphales

In contrast to Eurasia and North America, powdery mildews (Ascomycota, Erysiphales) are understudied in Australia. There are over 900 species known globally, with fewer than currently 60 recorded from Australia. Some of the Australian records are doubtful as the identifications were presumptive, being based on host plant-pathogen lists from overseas. The goal of this study was to provide the first comprehensive catalog of all powdery mildew species present in Australia. The project resulted in (i) an up-to-date list of all the taxa that have been identified in Australia based on published DNA barcode sequences prior to this study; (ii) the precise identification of 117 specimens freshly collected from across the country; and (iii) the precise identification of 30 herbarium specimens collected between 1975 and 2013. This study confirmed 42 species representing 10 genera, including two genera and 13 species recorded for the first time in Australia. In Eurasia and North America, the number of powdery mildew species is much higher. Phylogenetic analyses of powdery mildews collected from Acalypha spp. resulted in the transfer of Erysiphe acalyphae to Salmonomyces, a resurrected genus. Salmonomyces acalyphae comb. nov. represents a newly discovered lineage of the Erysiphales. Another taxonomic change is the transfer of Oidium ixodiae to Golovinomyces. Powdery mildew infections have been confirmed on 13 native Australian plant species in the genera Acacia, Acalypha, Cephalotus, Convolvulus, Eucalyptus, Hardenbergia, Ixodia, Jagera, Senecio, and Trema. Most of the causal agents were polyphagous species that infect many other host plants both overseas and in Australia. All powdery mildews infecting native plants in Australia were phylogenetically closely related to species known overseas. The data indicate that Australia is a continent without native powdery mildews, and most, if not all, species have been introduced since the European colonization of the continent

Palmageddon in Australia? A lethal disease of palms associated with a new phytoplasma in Cairns

A phytoplasma associated with a rapid lethal wilt of ornamental palms in Cairns was detected by nested and real time PCR. Leaf death progressed from older to younger leaves, culminating in meristem rot. With a maximum 16SrRNA gene sequence similarity of 96%, this phytoplasma is most closely related to, but not a member of, the novel taxon 'Candidatus Phytoplasma noviguineense'. The next most closely related sequences all belonged to phytoplasmas in the 16SrIV and 16SrXXII groups. 'Ca. P. noviguineense' and members of these groups are implicated in devastating diseases of coconut overseas and have never been recorded before in Australia. A key symptom in Cairns is shared with these exotic coconut diseases: dead leaves hang down, skirt like, before eventually falling. Phylogenetic trees comparing 16SrRNA and three ribosomal protein gene sequences against those of known candidatus phytoplasma species, plus other variants, confirmed the uniqueness of this phytoplasma. It was first detected in late 2017 in a Dypsis poivreana within the Cairns Botanic Gardens, (CBG). In 2018, it was also found in a Euterpe precatoria just outside the CBG and in a coconut palm (Cocos nucifera) and an Alexandrea palm (Archontophoenix alexandrae), about 2 km south east of the CBG. Later investigations up to March 2019 detected the phytoplasma in more dying palms. These were a Verschaffeltia splendida and a Brassiophoenix drymophloeodes in the CBG, a Euterpe sp. about 600m west of the CBG, a Phoenix sp. 1.5 km west of the CBG, and a Carpentaria palm (Carpentaria acuminata) about 3 km south of the CBG. Detections at six separate locations suggests a capable insect vector is also present. During these investigations, a total of 33 other palms tested negative for phytoplasma, strongly suggesting this phytoplasma could be a causal agent of serious disease, rather than just an occasional phloem inhabitant

Plant Virus and Virus-like Disease Threats to Australia’s North Targeted by the Northern Australia Quarantine Strategy

The Northern Australia Quarantine Strategy (NAQS) is a biosecurity initiative operated by the Australian federal government’s Department of Agriculture, Water and the Environment (DAWE). It is unique worldwide because it deals specifically with the potential arrival via unregulated pathways of exotic threats from overseas in a vast and sparsely populated region. It aims to protect the nation’s animal- and plant-based production industries, as well as the environment, from incursions of organisms from countries that lie immediately to the north. These are diseases, pests, and weeds present in these countries that are currently either absent from, or under active containment in, Australia and may arrive by natural or human-assisted means. This review article focuses on the plant viruses and virus-like diseases that are most highly targeted by the NAQS program. It presents eight pathogen species/group entries in the NAQS A list of target pathogens, providing an overview of the historical and current situation, and collates some new data obtained from surveillance activities conducted in northern Australia and collaborative work overseas

'Candidatus Phytoplasma dypsidis', a novel taxon associated with a lethal wilt disease of palms in Australia

A phytoplasma was initially detected in Dypsis poivriana by nested and real-time PCR from the botanical gardens in Cairns, Queensland, Australia in 2017. Further surveys in the Cairns region identified phytoplasma infections in eight additional dying ornamental palm species (Euterpe precatoria, Cocos nucifera, Verschaffeltia splendida, Brassiophoenix drymophloeodes, Burretiokentia hapala, Cyrtostachys renda, Reinhardtia gracilis, Carpoxylon macrospermum), a Phoenix species, a Euterpe species and two native palms (Archontophoenix alexandrae). Analysis of 16S rRNA gene sequences showed that this phytoplasma is distinct as it shared less than 97.5 % similarity with all other ‘Candidatus Phytoplasma’ species. At 96.3 % similarity, the most closely related formally described member of the provisional 'Ca. Phytoplasma'genus was 'Ca. Phytoplasma noviguineense', a novel taxon from the island of New Guinea found in monocotyledonous plants. It was slightly more closely related (96.6–96.8 %) to four palm-infecting strains from the Americas, which belong to strain group 16SrIV and which have not been assigned to a formal 'Candidatus Phytoplasma’ species taxon. Phylogenetic analysis of the 16S rRNA gene and ribosomal protein genes of the phytoplasma isolate from a dying coconut palm revealed that the phytoplasma represented a distinct lineage within the phytoplasma clade. As the nucleotide identity with other phytoplasmas is less than 97.5 % and the phylogenetic analyses show that it is distinct, a novel taxon 'Candidatus Phytoplasma dypsidis' is proposed for the phytoplasma found in Australia. Strain RID7692 (GenBank accession no. MT536195) is the reference strain. The impact and preliminary aspects of the epidemiology of the disease outbreak associated with this novel taxon are described

Modelling human-fire interactions: combining alternative perspectives and approaches

Although it has long been recognised that human activities affect fire regimes, the interactions between humans and fire are complex, imperfectly understood, constantly evolving, and lacking any kind of integrative global framework. Many different approaches are used to study human-fire interactions, but in general they have arisen in different disciplinary contexts to address highly specific questions. Models of human-fire interactions range from conceptual local models to numerical global models. However, given that each type of model is highly selective about which aspects of human-fire interactions to include, the insights gained from these models are often limited and contradictory, which can make them a poor basis for developing fire-related policy and management practices. Here, we first review different approaches to modelling human-fire interactions and then discuss ways in which these different approaches could be synthesised to provide a more holistic approach to understanding human-fire interactions. We argue that the theory underpinning many types of models was developed using only limited amounts of data and that, in an increasingly data-rich world, it is important to re-examine model assumptions in a more systematic way. All of the models are designed to have practical outcomes but are necessarily simplifications of reality and as a result of differences in focus, scale and complexity, frequently yield radically different assessments of what might happen. We argue that it should be possible to combine the strengths and benefits of different types of model through enchaining the different models, for example from global down to local scales or vice versa. There are also opportunities for explicit coupling of different kinds of model, for example including agent-based representation of human actions in a global fire model. Finally, we stress the need for co-production of models to ensure that the resulting products serve the widest possible community