Publications by authors named "Beach D"

Complex health system questions often have a case study (such as a country) as the unit of analysis. Process tracing, a method from policy studies, is a flexible approach for causal analysis within case studies, increasingly used in applied health research. The aim of this study was to identify the ways in which process tracing methods have been used in health research, and provide insights for best practice.

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In recent years, investment in workplace mental health and wellbeing has grown. However, there is little understanding of how resource allocation decisions are made in such settings. To ensure evaluative research can support resource allocation, a process-based understanding of decision-making would be helpful.

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Cyanobacteria produce diverse classes of toxins including microcystins, nodularins, anatoxins, cylindrospermopsins and saxitoxins, encompassing a range of chemical properties and mechanisms of toxicity. Comprehensive analysis of these toxins in cyanobacterial, environmental and biological samples generally requires multiple methods of extraction and analysis. In this work, a method was developed for the major classes of cyanotoxins, which comprised of a three-step liquid-solid extraction method using 75 % CHCN with 0.

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Robust prognostic and predictive factors for hepatocellular carcinoma, a leading cause of cancer-related deaths worldwide, have not yet been identified. Previous studies have identified potential HCC determinants such as genetic mutations, epigenetic alterations, and pathway dysregulation. However, the clinical significance of these molecular alterations remains elusive.

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Blooms of the red, filamentous cyanobacterium Planktothrix rubescens occur frequently in pre-alpine lakes in Europe, often with concomitant toxic microcystin (MC) production. Trophic transfer of MCs has been observed in bivalves, fish, and zooplankton species, while uptake of MCs into Diptera species could facilitate distribution of MCs into terrestrial food webs and habitats. In this study, we characterized a Planktothrix bloom in summer 2019 in Lake Mindelsee and tracked possible trophic transfer and/or bioaccumulation of MCs via analysis of phytoplankton, zooplankton (Daphnia) and emergent aquatic insects (Chaoborus, Chironomidae and Trichoptera).

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Proliferations of benthic cyanobacteria are increasingly in the public eye, with rising animal deaths associated with benthic rather than planktonic blooms. In early June 2021, two dogs died after consuming material on the shore of Shubenacadie Grand Lake, Nova Scotia. Preliminary investigations indicated anatoxins produced by benthic cyanobacterial mats were responsible for the deaths.

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Anatoxins (ATXs) are a potent class of cyanobacterial neurotoxins for which only a handful of structural analogues have been well characterized. Here, we report the development of an LC-HRMS/MS method for the comprehensive detection of ATXs. Application of this method to samples of benthic cyanobacterial mats and laboratory cultures showed detection of several new ATXs.

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Article Synopsis
  • * Researchers sequenced the DNA of 15 cyanobacterial isolates from these mats and found that while some could produce anatoxins, others could not, indicating a genetic variation among the isolates.
  • * The study revealed that toxigenic and non-toxigenic strains of Microcoleus from the Wolastoq River are closely related but are distinct subspecies, with toxigenic strains exhibiting longer genomes and more genes that may help them adapt to environmental changes.
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In July 2018 three dogs died after visiting the Wolastoq (Saint John River) near Fredericton, New Brunswick, in Atlantic Canada. All showed signs of toxicosis, and necropsies revealed non-specific pulmonary edema and multiple microscopic brain hemorrhages. Liquid chromatography-high-resolution mass spectrometry (LC-HRMS) analysis of vomitus and stomach contents as well as water and biota from the mortality sites confirmed the presence of anatoxins (ATXs), a class of potent neurotoxic alkaloids.

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Microcystins and nodularins, produced naturally by certain species of cyanobacteria, have been found to accumulate in aquatic foodstuffs such as fish and shellfish, resulting in a risk to the health of the seafood consumer. Monitoring of toxins in such organisms for risk management purposes requires the availability of certified matrix reference materials to aid method development, validation and routine quality assurance. This study consequently targeted the preparation of a mussel tissue reference material incurred with a range of microcystin analogues and nodularins.

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Toxic benthic cyanobacterial mats are increasingly reported worldwide as being responsible for animal mortalities due to their production of the potent neurotoxin anatoxin-a (ATX) and its analogues. Improved analytical methods for anatoxins are needed to address public health and watershed management challenges arising from extremely high spatial and temporal variability within impacted systems. We present the development, validation, and application of a direct analysis in real-time-high-resolution tandem mass spectrometry (DART-HRMS/MS) method for analysis of anatoxins in cyanobacterial field samples, including a simplified sample preparation approach.

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Development and characterization of biological and environmental matrix certified reference materials (CRMs) for organic analytes typically relies heavily on targeted analytical methods, such as liquid chromatography (LC) with triple-quadrupole mass spectrometry detection. LC with high-resolution mass spectrometry (LC‒HRMS) can also provide high quality data for both targeted and non-targeted analytes, with the potential for retrospective data analysis. Here, we demonstrate the utility of non-target analysis (NTA) using LC‒HRMS for profiling and stability assessment of a mussel tissue matrix CRM certified for several classes of marine algal toxins (CRM-FDMT1).

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Circadian rhythms are generated by interlocked transcriptional-translational feedback loops of circadian clock genes and their protein products. Mice homozygous for a functional deletion in the Period-2 gene ( mice) exhibit short free-running circadian periods and eventually lose behavioral circadian rhythmicity in constant darkness (DD). We investigated mice in DD for several months and identified a categorical sex difference in the dependence on for maintenance of circadian rhythms.

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Mind-body modalities are promising strategies to maintain the benefits gained after completion of conventional pulmonary rehabilitation in persons with COPD. In this pilot randomised controlled study we examined Tai Chi in persons with COPD after completing pulmonary rehabilitation. Participants were randomised 2:2:1 to Tai Chi (TC), usual care (UC) or group walking (GW) for 24 weeks.

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In this pilot feasibility randomized controlled trial, participants with moderate to severe COPD were randomized to a 12-week tai chi or MBB intervention. Participants were assessed at baseline, 12 weeks, and 24 weeks. Feasibility, as assessed by intervention adherence, was the primary outcome.

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Article Synopsis
  • The costimulatory receptor CD28 works alongside the T cell receptor (TCR) to enhance IL-2 production, cell survival, and proliferation, but the exact relationship between their signaling pathways is not fully understood.
  • Researchers discovered that TCR stimulation activates a signaling complex involving adaptors Gads, LAT, and SLP-76, where the phosphorylation of specific sites by the Tec-family kinase Itk plays a critical role.
  • The study reveals that phosphorylation of Gads at Y45 is crucial for promoting IL-2 transcription through TCR/CD28 signaling, suggesting a new regulatory mechanism that underscores the interdependence of TCR and CD28 pathways in T cell activation.
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Harmful cyanobacterial blooms, which frequently contain toxic secondary metabolites, are reported in aquatic environments around the world. More than two thousand cyanobacterial secondary metabolites have been reported from diverse sources over the past fifty years. A comprehensive, publically-accessible database detailing these secondary metabolites would facilitate research into their occurrence, functions and toxicological risks.

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Organizational change is a complex and critical issue in higher education today. Changes experienced across institutional systems have both short-term and long-term impact, making this phenomenon ripe for educational leadership research. Many universities and colleges have applied Kotter's (1995) eight-step change model prescriptively to implement academic initiatives, curriculum revisions, and strategic vision.

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Background: The fetal alcohol spectrum disorders (FASD) are among the most prevalent causes of neurodevelopmental disorders. The diagnosis is based on assessment of prenatal alcohol exposure, specific physical features identified with a dysmorphology examination, and neurobehavioral assessment. Prompt diagnosis of affected children is necessary to provide early intervention services in a timely manner; however, the availability of diagnostic expertise is limited.

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Background: Despite therapeutic advances, the management of chronic obstructive pulmonary disease (COPD) remains complex. There is growing interest in multidimensional, mind-body exercises to improve both physical and psychosocial aspects of COPD burden. Few US data are available in this population on tai chi (TC) a mind-body exercise incorporating physical activity, breathing and mindful awareness.

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Rationale: Anatoxins (ATXs) are a potent class of cyanobacterial neurotoxins that are increasingly problematic in drinking water reservoirs and recreational water bodies worldwide. Because of their high polarity and low molecular weight, analysis of ATXs is challenging and they can be considered underreported compared with other classes of cyanobacterial toxins. Improved screening methods are therefore needed to effectively assess their occurrence and concentrations in the environment.

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