Cellular-level mechanisms of polarity and their role in plant growth

Coordinated cell polarity fields are essential for plant and animal development. Several models have been proposed for how these cell polarity fields are established. However, it remains unclear how different models are related to each other and how coordinated cell polarity fields are generated. Here, I present a hypothesis that both plant and animal cell polarity fields are based on a common intracellular partitioning (IP) mechanism that spontaneously generates cell polarity independently from pre-established asymmetries. I show how plant polarity fields may be accounted for through an auxin-mediated indirect cell-cell coupling mechanism that coordinates polarities established by IP, and provides an explicit molecular hypothesis that is consistent with current experimental data. I show that this model behaves similarly to a flux-based model of plant polarity in several scenarios, and that these models make testable predictions that differ from those of published up-the-gradient models. To test the different plant models, I use kanadi1kanadi2 (kan1kan2) mutant Arabidopsis leaves, which develop ectopic outgrowths, as a simple system to study the dynamics of polarity reorientations. I compare contrasting model predictions with observed polarity changes and patterns of auxin-related gene expression preceding the development of ectopic outgrowths. Together with an analysis of wild-type leaves, this reveals that indirect cell-cell coupling and flux-based models are more compatible than the up-the-gradient model with patterns of auxin biosynthesis and import in leaves. I next show that the CUC2 transcription factor is essential for kan1kan2 outgrowth development. Through modelling and experiments, I show that CUC2-regulation of auxin biosynthesis most-likely plays an important role in polarity reorientations. Finally, I present models for how epidermal and subepidermal PIN polarity patterns may be coordinated and lead to changes in growth. This work reveals the value of comparing different computational models with experimental data when investigating mechanisms of polarity generation

Facilitating social coping-‘seeking emotional and practical support from others’-as a critical strategy in maintaining the family care of people with dementia

The aim of this study was to identify how the family care of people living with dementia could be supported to make reliance on family care sustainable in the long term despite the impact of stress. A Realist Evaluation (Pawson & Tilley, 1997) was conducted to investigate this aim. An initial review established ‘coping’ as a primary means of mediating stressors associated with caregiving. However, there was a need to specify which coping approaches/strategies are most effective. In-depth interviews were conducted with a purposive sample of family carers (n = 18) in a suburb in North East England from 2016 to 2017. Analysis of the data revealed ‘social coping’ (SC) that included an emotional support component as a critical mediator of family carer stress. Several key hindrances to the utilisation of SC, including underpinning causal factors, are explicated. Ways in which these hindrances might be overcome are discussed and guidelines introduced for how family carers, formal providers and practitioners can facilitate SC as a critical coping strategy in sustaining the family care of people with dementia over the long term

Exploring medicines reconciliation in the emergency assessment unit: staff perceptions and actual waiting times

Background Medicines reconciliation is the process of creating and maintaining the most accurate list possible of all medicines a patient is taking. If medicines reconciliation cannot be completed in a timely manner in hospital emergency assessment units (EAUs), delays in treatment can occur, potentially leading to deterioration of long-term and acute conditions, patient distress and complaints. Aim To obtain the perspectives of staff working on an EAU regarding the time patients wait for their medicines to be prescribed, including their awareness of practice and protocols. To determine the time from admission to the EAU until medicines reconciliation, and to identify if there was any time difference in medicines reconciliation according to the day of admission. Method This was a service evaluation in which staff working in one EAU in a teaching hospital in the north east of England were asked to complete a survey in December 2017. The staff survey aimed to ascertain: whether staff were aware of any guidance relating to medicines reconciliation times; how long they thought the average waiting time was for medicines reconciliation; and if they thought there were implications for patients or staff as a result of time spent waiting for medicines reconciliation. In addition, an audit was performed analysing medicines reconciliation times for all patients admitted to the EAU during the month of December 2017. Results A total of 30 staff members responded to the survey. While 40% (n=12) of respondents believed that the EAU had an efficient system in place for timely medicines reconciliation, 90% (n=27) believed the unit could still improve. Almost half the respondents (47%, n=14) perceived a delay in medicines reconciliation could result in exacerbation of patients’ physical conditions. The clinical audit identified considerable variation in medicines reconciliation times, ranging from seven minutes to almost 24 hours. However, most medicines (82%) were reconciled within six hours. Conclusion This service evaluation found that the median time after arrival in the EAU until completion of medicines reconciliation was two hours 48 minutes. However, almost one fifth of patients had to wait for more than six hours, and in one instance almost 24 hours. One potential solution could be increasing the involvement of hospital pharmacists or pharmacy technicians in medicines reconciliation

Use of heavy metals in swine feed and its association with the co-selection of metal tolerant and multi-drug resistant Salmonella

This study was conducted to characterize the role of chemical interventions, biocides and heavy metal micronutrients, in particular, in swine production systems on the emergence of heavy metal and biocide tolerant Salmonella and its association with antimicrobial resistance. A total of 353 Salmonella isolates with different antimicrobial resistance profiles identified from 36 barns exposed to three different classes of biocides were analyzed. The sources of isolates included feed (n=30), fecal (n=226), and environment (n=97) samples that were systematically selected

Association of Pathogen Load in Pigs with Retail Pork Contamination.

Salmonella and Campylobacter are estimated to cause 3.9 million illnesses annually in the United States, and most of these illnesses are food-related. Pigs can be sub-clinically infected with these pathogens and fecal contamination of meat during processing is a food safety risk. Quantitative measures of foodborne safety risk are rarely reported and are a critical data gap for development of quantitative risk assessments. The goal of this study was to determine the association between the concentration of Salmonella and Campylobacter in porcine feces and hide with concentrations in meat

Prevalence and Antimicrobial Resistance of Salmonella, E. coli, and Campylobacter in Pigs from Swine Producing States in the United States

The purpose of the study was to determine the prevalence and antimicrobial susceptibility of Salmonella, Campylobacter and generic E. coli (commensal bacteria which may harbor antimicrobial resistance genes) from swine feces collected over one year from the top three swine producing states (Iowa, North Carolina, and Minnesota), which represent 51% of the total pig crop in the U.S, plus Ohio. The prevalence of Salmonella (n=462/4426), Campylobacter (n=994/1184) and E. coli (n=833/845) at the sample level was 10.4%, 98.6% and 83.6%, respectively

Alzheimer's Disease: The Resilience Approach to making the Family Care of People Living with Alzheimer's sustainable

With critical reliance on primary family carers of people living with Alzheimer’s disease (PWA) at an all-time high and set to increase markedly over the next few decades an urgent question concerns how this growing army of family carers will be supported in the future? The uniqueness and complexity of Alzheimer’s disease (AD) compared with other diseases and the myriad challenges it presents for family carers make such carers particularly vulnerable to the debilitating effects of chronic stress and its sequelae. The biopsychosocial pathways responsible for carer health deficits resulting from chronic exposure to the care environment are discussed. Further, a new epidemiological framework is introduced that attempts to capture how the dynamics at work within the AD care environment might lead it to become epidemiological in the sense that chronic exposure to it can uniquely generate carer disease outcomes. If the family care of PWA can potentially create an environment and dynamics within this that may be injurious to carers themselves, leading to premature cessation of informal care, a central issue for policy-makers and service providers concerns ‘who will care for the carers and how?’ Although the present article primarily focuses on family carers of PWA, the knowledge that carers’ health has a relatively direct impact on the capacity to carry out caregiving, as well as influencing the levels of harmony or disequilibrium that exists within the care environment, crucially means that carers’ health also impacts on the wellbeing of PWA as part of a closely knit reciprocal relationship-they are mutually bound. Further, while there is evidence to indicate that some family carers of PWA appear able to overcome the many challenges and potential attrition long-term care of a PWA can inflict on their own health, a further key question concerns how such carers manage despite adversity? What characteristics, assets and resources do these carers possess that perhaps sets them apart? Are there valuable lessons we can learn concerning how the family care of PWA might be made optimal while safeguarding family carers’ own health? This represents an important question since the vast majority of family carers, and moreover their care recipients, hope and desire to spend their final years, months, days together as a family rather than see their family member consigned to a formal institution. This article therefore argues the case for urgent public health action against the backdrop of the rising tide of AD globally. Presently, there is a lack of any clear consensus concerning how more productive care environments might be created that better safeguard both family carers’ health and by association PWA’s health. Moreover, there is a need to move beyond syntheses of findings from the available literature that are limited to descriptive accounts based on ‘outcomes’ and towards a deeper analysis of ‘process,’ i.e. by focusing on what intrinsically ‘works’ to support family carers of PWA and how these processes might be generated. In response, the present authors recently conducted a comprehensive Realist review of the current literature. How this review was conducted is briefly described, as are the broad findings that lead to the proposal of a new model of family care of PWA. The strengths and weaknesses of existing hypotheses are discussed for how carers can counteract the challenges to their own health that care of PWA can bring and a new hypothesis is proposed based on a Resilience approach to family care of PWA that links with humans’ ‘fight or flight’ response to stressors

Investigating what works to support family carers of people with dementia: a rapid realist review

Introduction - Advances in longevity and medicine mean that many more people in the UK survive life-threatening diseases but are instead susceptible to life-limiting diseases such as dementia. Within the next 10 years those affected by dementia in the UK is set to rise to over 1 million, making reliance on family care of people with dementia (PWD) essential. A central challenge is how to improve family carer support to offset the demands made by dementia care which can jeopardise carers’ own health. This review investigates ‘what works to support family carers of PWD’. Methods - Rapid realist review of a comprehensive range of databases. Results - Five key themes emerged: (1) extending social assets, (2) strengthening key psychological resources, (3) maintaining physical health status, (4) safeguarding quality of life and (5) ensuring timely availability of key external resources. It is hypothesized that these five factors combine and interact to provide critical biopsychosocial and service support that bolsters carer ‘resilience’ and supports the maintenance and sustenance of family care of PWD. Conclusions - ‘Resilience-building’ is central to ‘what works to support family carers of PWD’. The resulting model and Programme Theories respond to the burgeoning need for a coherent approach to carer support

Methicillin Resistant Staphylococcus aureus (MRSA) in market age pigs on-farm, at slaughter and retail pork

This study was conducted to determine the occurrence and prevalence of methicillin resistant Staphylococcus aureus (MRSA) in finishing pigs on-farm, at lairage and assess the likelihood of carriage at slaughter and retail levels. A cross-sectional study targeting ten cohorts of commercial swine farms was conducted for carriage of MRSA