The regulation of division of higher plant cells

Thesis from Leicester PolytechnicAcer pseudoplatanus L (English sycamore) cell suspension cultures provide an excellent system for controlled investigations into the regulation of cytokinesis. They exhibit 60-70% division synchrony on subculture, and produce predictable growth patterns in batch culture. Previous studies in these laboratories with partially synchronized cultures led to the hypothesis that a critical "trigger" concentration of endogenous IAA (approximately 500-750 ng 10 8 cells) is vital prior to each mitosis. In this present study a more effective induction technique has been employed. The cells were found to rapidly become nitrate and phosphate limited in batch culture. The addition of these nutrients after each cell division resulted in several highly synchronous divisions (80-90%). In"these cultures 'the IAA levels remained at a relatively stable level (50 ng 108 cells). Thus, the original hypothesis has been modified and it is now proposed that a critical minimum endogenous concentration of IAA is required to maintain cytokinesis. This IAA level may be optimal for an IAA binding protein. The nutrient feeding system was adapted for automation with the aid of a computer Interface. This automated system ensures,-- that the synchronization technique is more reliable and less time consuming. The endogenous cytokinins were studied during the first cell division. The individual levels were found to fluctuate with total cytokinin-like activity reaching a maxima -coincident with mitosis and/or cytokinesis. Z was the major cytokinin detected. This implicated the cytokinins as possible G2 --) M triggers. The Intracellular pH levels were estimated by 31p NMR spectroscopy. The cytoplasmic pH remained stable (approximately 7.5) during synchronous divisions and decreased as asynchrony developed. This may be a reflection of the nutrient status of the cells and/or the level optimal for"the distribution of IAA and/or other growth regulators. The cell cycle appears to be controlled by the various growth regulators and their receptors. It is apparent that the concentrations, availability and distribution of these substances is vital for the complex regulated cycle to ensue

Corpus consultation and advanced learners' writing skills in French

peer-reviewedIn the rapidly changing environment of language learning and teaching, electronic literacies have an increasingly important role to play. While much research on new literacies focuses on the World Wide Web, the aim in this study is to investigate the importance of corpus consultation as a new type of literacy which is of particular relevance in the context of language learning and teaching. After briefly situating the theoretical and pedagogical context of the study in relation to authenticity and learner autonomy, the paper describes an empirical study involving eight postgraduate students of French. As part of a Masters course they write a short text and subsequently attempt to improve it by using concordancing software to consult a small corpus containing texts on a similar subject. The analysis of the results reveals a significant number of changes made by the learners which may be classified as follows in order of frequency: grammatical errors (gender and agreement, prepositions, verb forms/mood, negation and syntax); misspellings, accents and hyphens; lexico- grammatical patterning (native language interference, choice of verb and inappropriate vocabulary); and capitalisation. The conclusion notes that the situation in which these students found themselves (i.e. faced with a text on which the teacher had indicated phrases which could be improved) is replicated in many cases every day, and suggests that corpus consultation may have a useful role to play in the context of interactive feedback, particularly in cases where traditional language learning resources are of little use.PUBLISHEDpeer-reviewe

Reverse-engineering risk

Three philosophical accounts of risk dominate the contemporary literature. On the probabilistic account, risk has to do with the probability of a disvaluable event obtaining; on the modal account, it has to do with the modal closeness of that event obtaining; on the normic account, it has to do with the normalcy of that event obtaining. The debate between these accounts has proceeded via counterexample-trading, with each account having some cases it explains better than others, and some cases that it cannot explain at all. In this article, we attempt to break the impasse between the three accounts of risk through a shift in methodology. We investigate the concept of risk via the method of conceptual reverse-engineering, whereby a theorist reconstructs the need that a concept serves for a group of agents in order to illuminate the shape of the concept: its intension and extension. We suggest that risk functions to meet our need to make decisions that reduce disvalue under conditions of uncertainty. Our project makes plausible that risk is a pluralist concept: meeting this need requires that risk takes different forms in different contexts. But our pluralism is principled: each of these different forms are part of one and the same concept, that has a ‘core-to-periphery’ structure, where the form the concept takes in typical cases (at its ‘core’) explains the form it takes in less typical cases (at its ‘periphery’). We then apply our findings to epistemic risk, to resolve an ambiguity in how ‘epistemic risk’ is standardly understood

Urogenital symptoms: prevalence, bother, associations and impact in 22 year-old women of the Raine Study

Introduction and hypothesis: Urogenital symptoms are prevalent in older women, but there is little data available on the prevalence, bother, impact and associations with low back pain (LBP), obesity, parity, mental health (MH) and quality of life (QOL) in young women. Our aim was to determine the prevalence, bother and impact of urogenital symptoms and to explore associations with LBP, obesity, parity, MH and QOL in 22 year-old women. Methods: This was a cross-sectional evaluation using data collected from 588 women in the Raine Study, a pregnancy cohort in which participants have been regularly followed up from birth until 22 years. Data was analysed using descriptive statistics, univariate comparisons and linear regression models. Results: Prevalence of urogenital symptoms were stress urinary incontinence (SUI) 6.3%, mixed urinary incontinence (MUI) 11.5%, leakage of drops 5.8%, urge urinary incontinence (UUI) 5.3%, bothersome urinary frequency 41.5%, difficulty emptying 11.8% and urogenital pain 22.9%. Urinary frequency, MUI, difficulty emptying and urogenital pain were most bothersome, whilst difficulty emptying and urogenital pain were associated with greatest impact. Urinary frequency, SUI, leakage of drops, difficulty emptying and urogenital pain were associated with current LBP and LBP ever. Difficulty emptying and urogenital pain were associated with chronic LBP. Urogenital symptoms were not associated with obesity or parity. Women with urogenital symptoms had significantly poorer scores on the Mental Component Score of the Short Form Health Survey (SF)-12 and all aspects of the Depression Anxiety Stress Score. Conclusions: Urogenital symptoms are prevalent in young women, bothersome for some and are associated with LBP, poorer MH and reduced QOL

Aging modulates the effects of ischemic injury upon mesenchymal cells within the renal interstitium and microvasculature

Abstract The renal mesenchyme contains heterogeneous cells, including interstitial fibroblasts and pericytes, with key roles in wound healing. Although healing is impaired in aged kidneys, the effect of age and injury on the mesenchyme remains poorly understood. We characterized renal mesenchymal cell heterogeneity in young vs old animals and after ischemia‐reperfusion‐injury (IRI) using multiplex immunolabeling and single cell transcriptomics. Expression patterns of perivascular cell markers (α‐SMA, CD146, NG2, PDGFR‐α, and PDGFR‐β) correlated with their interstitial location. PDGFR‐α and PDGFR‐β co‐expression labeled renal myofibroblasts more efficiently than the current standard marker α‐SMA, and CD146 was a superior murine renal pericyte marker. Three renal mesenchymal subtypes; pericytes, fibroblasts, and myofibroblasts, were recapitulated with data from two independently performed single cell transcriptomic analyzes of murine kidneys, the first dataset an aging cohort and the second dataset injured kidneys following IRI. Mesenchymal cells segregated into subtypes with distinct patterns of expression with aging and following injury. Baseline uninjured old kidneys resembled post‐ischemic young kidneys, with this phenotype further exaggerated following IRI. These studies demonstrate that age modulates renal perivascular/interstitial cell marker expression and transcriptome at baseline and in response to injury and provide tools for the histological and transcriptomic analysis of renal mesenchymal cells, paving the way for more accurate classification of renal mesenchymal cell heterogeneity and identification of age‐specific pathways and targets

Seeing lockdown through the eyes of children from around the world: Reflecting on a children's artwork project.

The COVID-19 pandemic created new challenges for children including access to education and limiting social and emotional connections to extended family, friends, and the community. Globally, opportunities for sharing children’s self-reported experiences during lockdown were limited. The primary aim of this project was to create an art-E-Book that reflects children’s experiences of life during the COVID-19 pandemic that could be shared with other children around the world. Secondly, we wanted to reflect on the consultation undertaken within the International Network of Child and Family Centered Care (INCFCC) using Gibbs (1988) reflective cycle framework. Children from around the world were invited to submit a piece of artwork that reflected their experience during the COVID-19 pandemic via a Qualtrics-survey in May 2020. The children’s artwork and written pieces were transcribed verbatim into an E-Book and the artwork was further placed into groups based on similarity of meaning. Fifty-five children from 17 countries submitted an artwork piece. Four groups were evident within the children’s artwork including infection control measures, positive experiences and emotions (connection to family, fun activities), negative experiences and emotions (social impact, emotional impact), and uniting children globally. The E-Book is available to download free of charge via the INCFCC website. The E-Book illustrates how children of all ages can provide meaningful insightful commentary and valuable information on their experiences during an unprecedented pandemic

Mental health problems in people with learning disabilities: prevention, assessment and management

This guideline covers preventing, assessing and managing mental health problems in people with learning disabilities in all settings (including health, social care, education, and forensic and criminal justice). It aims to improve assessment and support for mental health conditions, and help people with learning disabilities and their families and carers to be involved in their care

Mercury plumes in the global upper troposphere observed during flights with the CARIBIC observatory from May 2005 until June 2013

Tropospheric sections of flights with the CARIBIC (Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrumented Container) observatory from May 2005 until June 2013, are investigated for the occurrence of plumes with elevated Hg concentrations. Additional information on CO, CO, CH, NO, O, hydrocarbons, halocarbons, acetone and acetonitrile enable us to attribute the plumes to biomass burning, urban/industrial sources or a mixture of both. Altogether, 98 pollution plumes with elevated Hg concentrations and CO mixing ratios were encountered, and the Hg/CO emission ratios for 49 of them could be calculated. Most of the plumes were found overEast Asia, in the African equatorial region, over South America and over Pakistan and India. The plumes encountered over equatorial Africa and over South America originate predominantly from biomass burning, as evidenced by the low Hg/CO emission ratios andelevated mixing ratios of acetonitrile, CHCl and particle concentrations. The backward trajectories point to the regions around the Rift Valley and the Amazon Basin, with its outskirts, as the source areas. The plumes encountered over East Asia and over Pakistan and India are predominantly of urban/industrial origin, sometimes mixed with products of biomass/biofuel burning. Backward trajectories point mostly to source areas in China andnorthern India. The Hg/CO and Hg/CH emission ratios for several plumes are also presented and discussed