Haematozoa of wild catfishes in northern Australia

Very little is known about the diversity, prevalence, or pathogenicity of haematozoa in Australian freshwater fishes. Blood smears from 189 native catfishes, of six different species, from northern Australia were examined for haematozoa. Haematozoan infections were observed only in fishes from Queensland, at an overall prevalence of 0.191 (95% CI = 0.134-0.265). Intraerythrocytic haemogregarines were present in Neoarius graeffei from the Brisbane River at a prevalence of 0.35 (0.181-0.567). Trypanosomes were present in Tandanus species from four rivers, at prevalences ranging from 0.111 (0.020-0.330) to 1 (0.635-1), and in N. graeffei from one river in Queensland, at a prevalence of 0.063 (0.003-0.305). The haematozoans observed appeared to have little impact on their hosts. Tandanus spp. were significantly more likely to be infected with trypanosomes, suggesting a high parasite-host specificity. This is the first widespread survey of wild Australian freshwater catfishes for haematozoa, resulting in the first report of haemogregarines from Australian freshwater fish, and the first report of trypanosomes from Neoarius graeffei and Tandanus tropicanus

Mammal predation by an ariid catfish in a dryland river of Western Australia

The presence of the spinifex hopping mouse Notomys alexis in the diet of lesser salmon catfish Neoarius graeffei from the Ashburton River, Western Australia, is reported for the first time. The consumption of terrestrial mammals by Australian freshwater fishes is widely considered to be an infrequent occurrence, of limited importance to aquatic food webs. However, remains of N. alexis were present within the stomachs of 44% of N. graeffei sampled, constituting approximately 95% of the total stomach contents. These findings suggest that N. graeffei will consume large quantities of terrestrial vertebrates when available, and may represent a valuable energy source for this ecologically important species in dryland river

A modular and optimized single marker system for generating Trypanosoma brucei cell lines expressing T7 RNA polymerase and the tetracycline repressor

Here, we present a simple modular extendable vector system for introducing the T7 RNA polymerase and tetracycline repressor genes into Trypanosoma brucei. This novel system exploits developments in our understanding of gene expression and genome organization to produce a streamlined plasmid optimized for high levels of expression of the introduced transgenes. We demonstrate the utility of this novel system in bloodstream and procyclic forms of Trypanosoma brucei, including the genome strain TREU927/4. We validate these cell lines using a variety of inducible experiments that recapture previously published lethal and non-lethal phenotypes. We further demonstrate the utility of the single marker (SmOx) TREU927/4 cell line for in vivo experiments in the tsetse fly and provide a set of plasmids that enable both whole-fly and salivary gland-specific inducible expression of transgenes

A modular and optimized single marker system for generating Trypanosoma brucei cell lines expressing T7 RNA polymerase and the tetracycline repressor

Here, we present a simple modular extendable vector system for introducing the T7 RNA polymerase and tetracycline repressor genes into Trypanosoma brucei. This novel system exploits developments in our understanding of gene expression and genome organization to produce a streamlined plasmid optimized for high levels of expression of the introduced transgenes. We demonstrate the utility of this novel system in bloodstream and procyclic forms of Trypanosoma brucei, including the genome strain TREU927/4. We validate these cell lines using a variety of inducible experiments that recapture previously published lethal and non-lethal phenotypes. We further demonstrate the utility of the single marker (SmOx) TREU927/4 cell line for in vivo experiments in the tsetse fly and provide a set of plasmids that enable both whole-fly and salivary gland-specific inducible expression of transgenes

Untellable tales and uncertain futures: the unfolding narratives of young adults with cancer

In this paper, we examine the use of creative methods for understanding the experience of young adults aged between 16 and 30 years over a year following a cancer diagnosis. Exploring the renegotiation of identity, the narrative, longitudinal research design of the study demonstrated the unfolding process of the narrative work between participants and researcher. We used a combination of visual, spoken and reflexive psychosocial approaches to understand emergent narratives, many of which do not always find symbolisation in language. Our methodological approach focused on the difficult and sometimes ‘unspeakable’ nature of the young adults’ narratives, demonstrating the importance of different modes of communication in articulating complicated relations with uncertain futures. In this respect the links between narrative, social action and the imagining of possible futures are precarious. In this paper, we explore how untellable issues were explored, and the challenges of doing so

Renegotiation of identity in young adults with cancer: a longitudinal narrative study

Background Despite increasing international awareness of the impact of cancer on young adults, to date there has been limited in-depth research to understand their experiences following a diagnosis using a qualitative and longitudinal perspective. Objectives To explore the impact of cancer on young adults’ evolving sense of self and identity over one year from the time of diagnosis. In addition, to contribute further to an understanding of innovative research methods used to examine this experience. Design This was a longitudinal narrative study using visual methods and a psychosocial lens. Narrative was used to re-present experiences over time. Setting and Sample Recruitment was from a Principal Treatment Centre for Teenagers and Young Adults with Cancer and a Cancer Centre for Adults in the United Kingdom. Total population sampling was used over a six-month period, recruiting 18 young adults aged between 16 and 30, one to three months from a diagnosis of bone cancer, lymphoma or leukaemia. Methods In depth, free association narrative interviews at three-time points over a year were undertaken. Photographs were used to help with story-telling. Extensive reflexive field notes, debriefing and the use of a psychosocial research group, also formed data sources. Forty interviews were conducted with 18 participants: eight took part in three interviews, six in two interviews and four in one interview. Analysis focused on the holistic ‘case’ of the individual temporally. In-depth, visual images were analysed from discussion in the narrative text. Through memoing, coding and comparison, themes were developed across all cases and a conceptual framework developed. Results The conceptual framework illustrates the renegotiation of self over time through narrative. This was ‘biographically’ during young adult development and across ‘cancer time’; through the core components of: the inner world, (psyche, emotion and coping); self as embodied; self as relating to others, and self as relating to place. Stories indicated that there was a constant inter- relationship over time between the renegotiation of identity and adaption of biography. Conclusions The focus in this paper is on ‘the temporality of cancer’ through the first year from diagnosis, and the juxtaposed process of managing biographical and developmental milestones. The importance of developing health care and research which enables narrative and the patient's voice has been highlighted. It emphasizes the need for professionals to ‘be with’ and ‘walk alongside’ through the intensity of a biographically and identity changing illness.</p

Respect for the journey: a survivor-led investigation of undergoing psychotherapy assessment.

PURPOSE: Psychotherapy assessments are key decision points for both clients and services, carrying considerable weight on both sides. Limited research indicates that assessments have immediate and long-term impacts on clients, particularly where trauma has been experienced, affecting engagement with therapy. Understanding assessments from clients' perspectives can inform service development and improve client experience. METHODS: This is a survivor-led exploration of clients' experiences of undergoing assessment for talking therapies. Interviews were conducted with seven people who had undergone assessment for psychological therapies in third sector and NHS services. Interviews were recorded, transcribed and analysed thematically. RESULTS: The core theme was 'respect for the journey' reflecting the need expressed by participants for their life experiences prior to the assessment to be given full respect and consideration. Six sub-themes were identified: trauma and desperation, fear of judgement, search for trust and safety, sharing and withholding (a balancing act), feeling deconstructed, and finding hope. CONCLUSIONS: The findings highlight the heightened emotional power surrounding psychotherapy assessments, reflecting the journey participants had undertaken to reach this point. The dilemma facing clients at the heart of an assessment-how much to share and how much to withhold-demonstrates the importance for services and assessors of treating the journey a client has made to the assessment with care and respect. Findings indicate the value of services and practitioners undertaking a trauma-informed approach to assessment encounters

Quasar Selection Based on Photometric Variability

We develop a method for separating quasars from other variable point sources using SDSS Stripe 82 light curve data for ~10,000 variable objects. To statistically describe quasar variability, we use a damped random walk model parametrized by a damping time scale, tau, and an asymptotic amplitude (structure function), SF_inf. With the aid of an SDSS spectroscopically confirmed quasar sample, we demonstrate that variability selection in typical extragalactic fields with low stellar density can deliver complete samples with reasonable purity (or efficiency, E). Compared to a selection method based solely on the slope of the structure function, the inclusion of the tau information boosts E from 60% to 75% while maintaining a highly complete sample (98%) even in the absence of color information. For a completeness of C=90%, E is boosted from 80% to 85%. Conversely, C improves from 90% to 97% while maintaining E=80% when imposing a lower limit on tau. With the aid of color selection, the purity can be further boosted to 96%, with C= 93%. Hence, selection methods based on variability will play an important role in the selection of quasars with data provided by upcoming large sky surveys, such as Pan-STARRS and the Large Synoptic Survey Telescope (LSST). For a typical (simulated) LSST cadence over 10 years and a photometric accuracy of 0.03 mag (achieved at i~22), C is expected to be 88% for a simple sample selection criterion of tau>100 days. In summary, given an adequate survey cadence, photometric variability provides an even better method than color selection for separating quasars from stars.Comment: (v2) 50 pages, accepted to Ap

First detection of Edwardsiella ictaluri (Proteobacteria: Enterobacteriaceae) in wild Australian catfish

The bacterium Edwardsiella ictaluri is considered to be one of the most significant pathogens of farmed catfish in the United States of America and has also caused mortalities in farmed and wild fishes in many other parts of the world. E. ictaluri is not believed to be present in wild fish populations in Australia, although it has previously been detected in imported ornamental fishes held in quarantine facilities. In an attempt to confirm freedom from the bacterium in Australian native fishes, we undertook a risk-based survey of wild catfishes from 15 sites across northern Australia. E. ictaluri was detected by selective culturing, followed by DNA testing, in Wet Tropics tandan (Tandanus tropicanus) from the Tully River, at a prevalence of 0.40 (95% CI 0.21–0.61). The bacterium was not found in fishes sampled from any of the other 14 sites. This is the first report of E. ictaluri in wild fishes in Australia

The potential role of hybridization in diversification and speciation in an insular plant lineage: insights from synthetic interspecific hybrids

Hybridization is recognized as an important process in plant evolution, and this may be particularly true for island plants where several biotic and abiotic factors facilitate interspecific hybridization. Although rarely done, experimental studies could provide insights into the potential of natural hybridization to generate diversity when species come into contact in the dynamic island setting. The potential of hybridization to generate morphological variation was analysed within and among 12 families (inbred lines) of an F4 hybrid generation between two species of Tolpis endemic to the Canary Islands. Combinations of characters not seen in the parents were present in hybrids. Several floral and vegetative characters were transgressive relative to their parents. Morphometric studies of floral, vegetative and fruit characters revealed that several F4 families were phenotypically distinct from other families, and from their parents. The study demonstrates that morphologically distinct pollen-fertile lines, potentially worthy of taxonomic recognition if occurring in nature, can be generated in four generations. The ability of the hybrid lines to set self-seed would reduce gene flow among the lines, and among the hybrids and their parental species. Selfing would also facilitate the fixation of characters within each of the lines. Overall, the results show the considerable potential of hybridization for generating diversity and distinct phenotypes in island lineages