The TatC component of the twin-arginine protein translocase functions as an obligate oligomer

The Tat protein export system translocates folded proteins across the bacterial cytoplasmic membrane and the plant thylakoid membrane. The Tat system in Escherichia coli is composed of TatA, TatB and TatC proteins. TatB and TatC form an oligomeric, multivalent receptor complex that binds Tat substrates, while multiple protomers of TatA assemble at substrate-bound TatBC receptors to facilitate substrate transport. We have addressed whether oligomerisation of TatC is an absolute requirement for operation of the Tat pathway by screening for dominant negative alleles of tatC that inactivate Tat function in the presence of wild-type tatC. Single substitutions that confer dominant negative TatC activity were localised to the periplasmic cap region. The variant TatC proteins retained the ability to interact with TatB and with a Tat substrate but were unable to support the in vivo assembly of TatA complexes. Blue-native PAGE analysis showed that the variant TatC proteins produced smaller TatBC complexes than the wild-type TatC protein. The substitutions did not alter disulphide crosslinking to neighbouring TatC molecules from positions in the periplasmic cap but abolished a substrate-induced disulphide crosslink in transmembrane helix 5 of TatC. Our findings show that TatC functions as an obligate oligomer.</p

Influential factors of spousal relationship quality in couples living with dementia – A narrative synthesis systematic review

Aim The aim of this systematic review is to identify factors that influence relationship quality in couples living with dementia. Previous research has shown how maintaining a positive spousal relationship quality is important for quality of life and coping for both the caregiver and the person with dementia. Knowledge of influential factors could contribute to a deeper understanding of the value of a couple-centred clinical practice and research, within the field of dementia. Research design and methods Systematic procedures to database search, screening, data extraction and synthesis were followed. Qualitative, quantitative and mixed methods studies were included. A narrative synthesis was conducted through narrative summaries of included studies, thematic analysis and narrative descriptions of factors influencing relationship quality. Results 39 studies were included in the study: 28 qualitative, 8 quantitative and 3 mixed methods. Through the narrative synthesis, 20 factors were identified. The factors were grouped into two overarching themes: The world of us and The world outside of us, and further to six influencing factor categories: (1) Attitudes and strategies, (2) Behaviour and activities, (3) Emotional connectedness, (4) Activities and experiences outside of the home, (5) Social behaviour and roles, and (6) Belonging and safety. Discussion and conclusion The identified factors influence relationship quality in couples living with dementia on various levels. The findings of this review study should inform clinical, couple-centred dementia care practise and intervention studies, and further research should seek to gain deeper understandings of the individual factors and broader understandings of the correlations between factors

Development and implementation of a national online application system for cross-jurisdictional linked data

The Population Health Research Network (PHRN) is an Australian national data linkage infrastructure that links a wide range of health and human services data in privacy-preserving ways. The data linkage infrastructure enables researchers to apply for access to routinely collected, linked, administrative data from the six states and two territories which make up the Commonwealth of Australia, as well as data collected by the Australian Government. The PHRN is a distributed network where data is collected and managed at the respective jurisdictional and/or cross-jurisdictional levels. As a result, access to linked data from multiple jurisdictions requires complex approval processes. This paper describes Australia's approach to enabling access to linked data from multiple jurisdictions. It covers the identification of, and agreement to, a minimum set of data items to be included in a unified national application form, the development and implementation of a national online application system and the harmonisation of business processes for cross-jurisdictional research projects. Utilisation of the online application system and the ongoing challenges of data linkage across jurisdictions are discussed. Changes to the data custodian and ethics committee approval criteria were out of scope for this project

DMSP production by coral-associated bacteria

Dimethylsulfoniopropionate (DMSP) is an important molecule in the marine sulfur cycle, produced in large amounts by corals and their dinoflagellate endosymbionts, Symbiodiniaceae. Although corals are known to harbour bacteria that can catabolise DMSP, the recent discovery of bacteria capable of producing DMSP in coastal and deep-sea environments raises the possibility of a bacterial contribution to the DMSP output of corals. Here, 157 bacteria associated with four common coral species were isolated and screened for their ability to produce DMSP by targeting dsyB, a key gene involved in DMSP biosynthesis. Approximately 9% (14 out of 157) of the bacterial isolates harboured dsyB, all being members of the Alphaproteobacteria. The ability of these isolates to produce DMSP was confirmed by liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) measurements. A dsyB-harbouring strain, Shimia aestuarii AMM-P-2, was selected for genome sequencing. This strain harbours the complete genetic machinery to (i) assimilate sulfate and synthesise the DMSP precursors, cysteine and methionine; (ii) demethylate DMSP and generate methanethiol; (iii) cleave DMSP, generating dimethyl sulfide (DMS) and acrylate; and (iv) utilise or detoxify acrylate. The impacts of varied environmental factors (temperature, salinity, light and UV radiation) on S. aestuarii AMM-P-2 DMSP biosynthesis were characterised. DMSP levels in S. aestuarii AMM-P-2 increased almost two-fold under both hypersaline conditions (40 PSU) and high UV exposure. DMSP catabolism through the cleavage pathway also increased under these conditions, producing the antioxidants DMS and acrylate, a potential response to the oxidative stress generated. Overall, our results reveal that coral-associated bacteria can synthesize DMSP and may therefore contribute to DMSP production by the coral holobiont

HOMESIDE: Home-based family caregiver-delivered music and reading interventions for people living with dementia: Protocol of a randomised controlled trial

Introduction: Pharmacological interventions to address behavioural and psychological symptoms of dementia (BPSD) can have undesirable side effects, therefore non-pharmacological approaches to managing symptoms may be preferable. Past studies show that music therapy can reduce BPSD, and other studies have explored how formal caregivers use music in their caring roles. However, no randomised study has examined the effects on BPSD of music interventions delivered by informal caregivers (CGs) in the home setting. Our project aims to address the need for improved informal care by training cohabiting family CGs to implement music interventions that target BPSD, and the quality of life (QoL) and well-being of people with dementia (PwD) and CGs. Methods and analysis: A large international three-arm parallel-group randomised controlled trial will recruit a sample of 495 dyads from Australia, Germany, UK, Poland and Norway. Dyads will be randomised equally to standard care (SC), a home-based music programme plus SC, or a home-based reading programme plus SC for 12 weeks. The primary outcome is BPSD of PwD (measured using the Neuropsychiatric Inventory-Questionnaire). Secondary outcomes will examine relationship quality between CG and PwD, depression, resilience, competence, QoL for CG and QoL for PwD. Outcomes will be collected at baseline, at the end of the 12-week intervention and at 6 months post randomisation. Resource Utilisation in Dementia will be used to collect economic data across the life of the intervention and at 6-month follow-up. We hypothesise that the music programme plus SC will generate better results than SC alone (primary comparison) and the reading programme plus SC (secondary comparison). Ethics and dissemination: Ethical approval has been obtained for all countries. Results will be presented at national and international conferences and published in scientific journals and disseminated to consumer and caregiver representatives and the community

Harnessing Placebo Effects in Primary Care: Using the Person-Based Approach to Develop an Online Intervention to Enhance Practitioners' Communication of Clinical Empathy and Realistic Optimism During Consultations.

Background: Empathic communication and positive messages are important components of "placebo" effects and can improve patient outcomes, including pain. Communicating empathy and optimism to patients within consultations may also enhance the effects of verum, i.e., non-placebo, treatments. This is particularly relevant for osteoarthritis, which is common, costly and difficult to manage. Digital interventions can be effective tools for changing practitioner behavior. This paper describes the systematic planning, development and optimization of an online intervention-"Empathico"-to help primary healthcare practitioners enhance their communication of clinical empathy and realistic optimism during consultations. Methods: The Person-Based Approach to intervention development was used. This entailed integrating insights from placebo and behavior change theory and evidence, and conducting primary and secondary qualitative research. Systematic literature reviews identified barriers, facilitators, and promising methods for enhancing clinical empathy and realistic optimism. Qualitative studies explored practitioners' and patients' perspectives, initially on the communication of clinical empathy and realistic optimism and subsequently on different iterations of the Empathico intervention. Insights from the literature reviews, qualitative studies and public contributor input were integrated into a logic model, behavioral analysis and principles that guided intervention development and optimization. Results: The Empathico intervention comprises 7 sections: Introduction, Empathy, Optimism, Application of Empathico for Osteoarthritis, Reflection on my Consultations, Setting Goals and Further Resources. Iterative refinement of Empathico, using feedback from patients and practitioners, resulted in highly positive feedback and helped to (1) contextualize evidence-based recommendations from placebo studies within the complexities of primary healthcare consultations and (2) ensure the intervention addressed practitioners' and patients' concerns and priorities. Conclusions: We have developed an evidence-based, theoretically-grounded intervention that should enable practitioners to better harness placebo effects of communication in consultations. The extensive use of qualitative research throughout the development and optimization process ensured that Empathico is highly acceptable and meaningful to practitioners. This means that practitioners are more likely to engage with Empathico and make changes to enhance their communication of clinical empathy and realistic optimism in clinical practice. Empathico is now ready to be evaluated in a large-scale randomized trial to explore its impact on patient outcomes

The genomic basis of adaptive evolution in threespine sticklebacks

Marine stickleback fish have colonized and adapted to thousands of streams and lakes formed since the last ice age, providing an exceptional opportunity to characterize genomic mechanisms underlying repeated ecological adaptation in nature. Here we develop a high-quality reference genome assembly for threespine sticklebacks. By sequencing the genomes of twenty additional individuals from a global set of marine and freshwater populations, we identify a genome-wide set of loci that are consistently associated with marine–freshwater divergence. Our results indicate that reuse of globally shared standing genetic variation, including chromosomal inversions, has an important role in repeated evolution of distinct marine and freshwater sticklebacks, and in the maintenance of divergent ecotypes during early stages of reproductive isolation. Both coding and regulatory changes occur in the set of loci underlying marine–freshwater evolution, but regulatory changes appear to predominate in this well known example of repeated adaptive evolution in nature.National Human Genome Research Institute (U.S.)National Human Genome Research Institute (U.S.) (NHGRI CEGS Grant P50-HG002568

A database of marine phytoplankton abundance, biomass and species composition in Australian waters

There have been many individual phytoplankton datasets collected across Australia since the mid 1900s, but most are unavailable to the research community. We have searched archives, contacted researchers, and scanned the primary and grey literature to collate 3,621,847 records of marine phytoplankton species from Australian waters from 1844 to the present. Many of these are small datasets collected for local questions, but combined they provide over 170 years of data on phytoplankton communities in Australian waters. Units and taxonomy have been standardised, obviously erroneous data removed, and all metadata included. We have lodged this dataset with the Australian Ocean Data Network (http://portal.aodn.org.au/) allowing public access. The Australian Phytoplankton Database will be invaluable for global change studies, as it allows analysis of ecological indicators of climate change and eutrophication (e.g., changes in distribution; diatom:dinoflagellate ratios). In addition, the standardised conversion of abundance records to biomass provides modellers with quantifiable data to initialise and validate ecosystem models of lower marine trophic levels

Enhanced hyporheic exchange flow around woody debris does not increase nitrate reduction in a sandy streambed

Anthropogenic nitrogen pollution is a critical problem in freshwaters. Although riverbeds are known to attenuate nitrate, it is not known if large woody debris (LWD) can increase this ecosystem service through enhanced hyporheic exchange and streambed residence time. Over a year, we monitored the surface water and pore water chemistry at 200 points along a ~50m reach of a lowland sandy stream with three natural LWD structures. We directly injected 15N-nitrate at 108 locations within the top 1.5m of the streambed to quantify in situ denitrification, anammox and dissimilatory nitrate reduction to ammonia, which, on average, contributed 85%, 10% and 5% of total nitrate reduction, respectively. Total nitrate reducing activity ranged from 0-16µM h-1 and was highest in the top 30cm of the stream bed. Depth, ambient nitrate and water residence time explained 44% of the observed variation in nitrate reduction; fastest rates were associated with slow flow and shallow depths. In autumn, when the river was in spate, nitrate reduction (in situ and laboratory measures) was enhanced around the LWD compared with non-woody areas, but this was not seen in the spring and summer. Overall, there was no significant effect of LWD on nitrate reduction rates in surrounding streambed sediments, but higher pore water nitrate concentrations and shorter residence times, close to LWD, indicated enhanced delivery of surface water into the streambed under high flow. When hyporheic exchange is too strong, overall nitrate reduction is inhibited due to short flow-paths and associated high oxygen concentrations