27 research outputs found

    Critical Approach to Reflexivity in Grounded Theory

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    A problem with the popular desire to legitimate one’s research through the inclusion of reflexivity is its increasingly uncritical adoption and practice, with most researchers failing to define their understandings, specific positions, and approaches. Considering the relative recentness with which reflexivity has been explicitly described in the context of grounded theory, guidance for incorporating it within this research approach is currently in the early stages. In this article, we illustrate a three-stage approach used in a grounded theory study of how parents of children with autism navigate intervention. Within this approach, different understandings of reflexivity are first explored and mapped, a methodologically consistent position that includes the aspects of reflexivity one will address is specified, and reflexivity-related observations are generated and ultimately reported. According to the position specified, we reflexively account for multiple researcher influences, including on methodological decisions, participant interactions and data collection, analysis, writing, and influence of the research on the researcher. We hope this illustrated approach may serve both as a potential model for how researchers can critically design and implement their own context-specific approach to reflexivity, and as a stimulus for further methodological discussion of how to incorporate reflexivity into grounded theory research

    Genome of the marsupial Monodelphis domestica reveals innovation in non-coding sequences

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    We report a high-quality draft of the genome sequence of the grey, short-tailed opossum (Monodelphis domestica). As the first metatherian (\u27marsupial\u27) species to be sequenced, the opossum provides a unique perspective on the organization and evolution of mammalian genomes. Distinctive features of the opossum chromosomes provide support for recent theories about genome evolution and function, including a strong influence of biased gene conversion on nucleotide sequence composition, and a relationship between chromosomal characteristics and X chromosome inactivation. Comparison of opossum and eutherian genomes also reveals a sharp difference in evolutionary innovation between protein-coding and non-coding functional elements. True innovation in protein-coding genes seems to be relatively rare, with lineage-specific differences being largely due to diversification and rapid turnover in gene families involved in environmental interactions. In contrast, about 20% of eutherian conserved non-coding elements (CNEs) are recent inventions that postdate the divergence of Eutheria and Metatheria. A substantial proportion of these eutherian-specific CNEs arose from sequence inserted by transposable elements, pointing to transposons as a major creative force in the evolution of mammalian gene regulation. ©2007 Nature Publishing Group

    Hepatic and renal end-organ damage in the Fontan circulation: a report from the Australian and New Zealand Fontan Registry

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    Background: Hepatic and renal dysfunction have been observed in survivors of the Fontan procedure, however their incidence and associated factors remain poorly defined. Methods: A total of 152 participants from a Registry of 1528 patients underwent abdominal ultrasound, transient elastography (FibroScan), serum fibrosis score (FibroTest), in vivo Tc-99m DTPA measurement of glomerular filtration rate (mGFR), and urine albumin-creatinine ratio (ACR). Results: Mean age and time since Fontan were 19.8 ± 9.3 and 14.1 ± 7.6 years, respectively. Features suggestive of hepatic fibrosis were observed on ultrasound in 87/143 (61%) and no patient was diagnosed with hepatocellular carcinoma. FibroScan median kPa was ≥10 in 117/133 (88%), ≥15 in 75/133 (56%), and ≥20 in 41/133 (31%). Fifty-four patients (54/118, 46%) had a FibroTest score ≥0.49 (equivalent to ≥F2 fibrosis). FibroTest score correlated with FibroScan value (r = 0.24, p = 0.015) and ACR (r = 0.29, p = 0.002), and patients with ultrasound features of hepatic fibrosis had a higher FibroScan median kPa (19.5 vs 15.4, p = 0.002). Renal impairment was mild (mGFR 60–89 ml/min/1.73 m) in 46/131 (35%) and moderate (mGFR 30–59 ml/min/1.73 m) in 3/131 (2%). Microalbuminuria was detected in 52/139 participants (37%). By multivariable analysis, time since Fontan was associated with increased FibroScan median kPa (β = 0.89, 95% CI 0.54–1.25, p = 0.002) and decreased mGFR (β = −0.77, 95% CI −1.29–0.24, p = 0.005). Conclusions: In the second decade after Fontan hepatic and renal structure and function are abnormal in a significant number of patients: close to 60% have ultrasonographic evidence of structural hepatic abnormalities, 46% have elevated serum hepatic fibrosis scores, and 57% have either reduced glomerular filtration rate or microalbuminuria. Hepatic and renal function should be monitored for potential impacts on outcomes after Fontan completion

    Multi-Platform Next-Generation Sequencing of the Domestic Turkey (Meleagris gallopavo): Genome Assembly and Analysis

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    The combined application of next-generation sequencing platforms has provided an economical approach to unlocking the potential of the turkey genome

    Machine Learning Identifies Stemness Features Associated with Oncogenic Dedifferentiation.

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    Cancer progression involves the gradual loss of a differentiated phenotype and acquisition of progenitor and stem-cell-like features. Here, we provide novel stemness indices for assessing the degree of oncogenic dedifferentiation. We used an innovative one-class logistic regression (OCLR) machine-learning algorithm to extract transcriptomic and epigenetic feature sets derived from non-transformed pluripotent stem cells and their differentiated progeny. Using OCLR, we were able to identify previously undiscovered biological mechanisms associated with the dedifferentiated oncogenic state. Analyses of the tumor microenvironment revealed unanticipated correlation of cancer stemness with immune checkpoint expression and infiltrating immune cells. We found that the dedifferentiated oncogenic phenotype was generally most prominent in metastatic tumors. Application of our stemness indices to single-cell data revealed patterns of intra-tumor molecular heterogeneity. Finally, the indices allowed for the identification of novel targets and possible targeted therapies aimed at tumor differentiation

    Patterned afferent activity and synaptic plasticity in the magnocellular neurosecretory system

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    The organum vasculosum of the lamina terminalis (OVLT) is a central osmoreceptor which regulates neurohypophysial hormone release through glutamatergic synapses onto hypothalamic magnocellular neurosecretory cells (MNC's). Previous studies have shown that OVLT neurons can express low threshold spikes which, in other neurons, contribute to rhythmic firing. Electrophysiological recordings were therefore obtained in the medial OVLT in superfused explants of rat hypothalamus, which was found to contain neurons projecting to MNC's in the supraoptic nucleus. The OVLT neurons recorded revealed the presence of tonic firing at varying frequencies (0-40 Hz), as well as two distinct forms of bursting activity. Among these, clustered firing featured the highest frequencies (up to 100 Hz), and was observed in 31% of the neurons studied. The effects of two conditioning protocols on synaptic function were investigated by examining excitatory postsynaptic potentials (EPSP's) in MNC's during electrical stimulation of the OVLT. Trains of 100 Hz stimulation lasting 1 s were found to induce post-tetanic potentiation and long lasting potentiation (>>1 hr). Patterned stimulation mimicking clustered firing evoked only short-term (<<30 s) increases in EPSP amplitude capable of increasing the probability of spike discharge in MNC's. Activity patterns adopted by OVLT neurons may therefore be important for the regulation of neurohypophysial hormone release and body fluid homeostasis in vivo

    Calling for a Shared Understanding of Sampling Terminology in Qualitative Research

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    In this article we present the critical analysis of a recent methods overview, authored by McCrae and Purssell, as a means to highlight and address several important ambiguities and misunderstandings associated with terminology commonly used to describe sampling in qualitative research. We share several definitive understandings of sampling-related issues, which have been informed by a rigorous analysis of the methods literature from another earlier methods overview focused more broadly on sampling in qualitative research. Specifically, we address ambiguities and inconsistencies related to what can be sampled in qualitative research (the sampling unit), the concept of theoretical sampling, the term purposeful sampling, the appropriateness of initial sampling in grounded theory, and the need to distinguish between the functions of reporting one’s sampling methods and describing the final participant sample. Finally, we argue that a continued lack of clarity in the language we use to describe what we do erodes the real and perceived quality of qualitative research. We point to the important role of methods overviews both for focusing attention on underdeveloped research methods topics and as a source of solutions to methodological problems

    Service access experiences of immigrant and refugee caregivers of autistic children in Canada: A scoping review.

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    Primary caregivers are the main mediators of care for children with an autism diagnosis in Canada, and the navigation process to gain access to autism-related services is known to be a major burden. These challenges to service access are compounded for newcomers to Canada, which include immigrants and refugees. The purpose of this scoping review is to describe the available research on Canadian newcomer caregiver experiences navigating and accessing autism-related services. After a systematic search and screening process, 28 studies were included. Data were extracted regarding the populations, study aims, and themes reported. Included studies characterized barriers and facilitators to service access and navigation specific to immigrants, while limited information was available for refugees. Based on the existing literature, the authors provide recommendations for possible research approaches, populations to include, and themes to examine in future research to promote health equity in Canadian autism service access
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