554 research outputs found
Heavy metal research in Vietnam: an overview
Extended abstract.B.A. Zarcinas, M.J. McLaughlin, Pham Quang Ha and G. Cozen
Geochemical indices allow estimation of heavy metal background concentration in soils
Defining background concentrations for heavy metals in soils is essential for recognizing and managing soil pollution. However, background concentrations of metals in soils can vary naturally by several orders of magnitude. Moreover, many soils have also been subject to unquantifiable anthropogenic inputs of metals, in some cases, for centuries. Hence determination of heavy metal background concentrations in soils has to date been fraught with difficulty. Here we demonstrate that there are associations between the background heavy metal and Fe or Mn contents in soils which appear to be consistent for seven important heavy metals of environmental concern. The relationships are remarkably independent of both soil type and climatic setting. These observations provide the basis for a series of general equations from which it is proposed Southeast Asian including Australian, and possibly worldwide background concentrations for As, Cr, Co, Cu, Ni, Pb, and Zn in soils can be derived.R. E. Hamon, M. J. McLaughlin, R. J. Gilkes, A. W. Rate, B. Zarcinas, A. Robertson, G. Cozens, N. Radford and L. Bettena
Modelling the toxicity of copper and zinc to wheat and other crops and incorporation of the results into a proposed framework to derive biosolids guidelines
The application of biosolids to land can have both beneficial and detrimental environmentaleffects. The positive effects can arise from nutrients and organic carbon in the biosolids whilethe negative effects generally arise because of the contamination associated with biosolids(e.g. Broos et al., 2006; Heemsbergen et al., 2006; McLaughlin et al., 2006) but can also arisedue to excessive ammonia (Whatmuff et al., 2006). Therefore, any regulatory guidelinesdeveloped to manage the land application of biosolids must be able to enhance the beneficialeffects and minimise the deleterious effects
'It gives you an understanding you can't get from any book.' The relationship between medical students' and doctors' personal illness experiences and their performance: a qualitative and quantitative study
Background: anecdotes abound about doctors' personal illness experiences and the effect they have on their empathy and care of patients. We formally investigated the relationship between doctors' and medical students' personal illness experiences, their examination results, preparedness for clinical practice, learning and professional attitudes and behaviour towards patients.Methods: newly-qualified UK doctors in 2005 (n = 2062/4784), and two cohorts of students at one London medical school (n = 640/749) participated in the quantitative arm of the study. 37 Consultants, 1 Specialist Registrar, 2 Clinical Skills Tutors and 25 newly-qualified doctors participated in the qualitative arm. Newly-qualified doctors and medical students reported their personal illness experiences in a questionnaire. Doctors' experiences were correlated with self-reported preparedness for their new clinical jobs. Students' experiences were correlated with their examination results, and self-reported anxiety and depression. Interviews with clinical teachers, newly-qualified doctors and senior doctors qualitatively investigated how personal illness experiences affect learning, professional attitudes, and behaviour.Results: 85.5% of newly-qualified doctors and 54.4% of medical students reported personal illness experiences. Newly-qualified doctors who had been ill felt less prepared for starting work (p < 0.001), but those who had only experienced illness in a relative or friend felt more prepared (p = 0.02). Clinical medical students who had been ill were more anxious (p = 0.01) and had lower examination scores (p = 0.006). Doctors felt their personal illness experiences helped them empathise and communicate with patients. Medical students with more life experience were perceived as more mature, empathetic, and better learners; but illness at medical school was recognised to impede learning.Conclusion: the majority of the medical students and newly qualified doctors we studied reported personal illness experiences, and these experiences were associated with lower undergraduate examination results, higher anxiety, and lower preparedness. However reflection on such experiences may have improved professional attitudes such as empathy and compassion for patients. Future research is warranted in this area
Dopamine Augmented Rehabilitation in Stroke (DARS): a multicentre double-blind, randomised controlled trial of co-careldopa compared with placebo, in addition to routine NHS occupational and physical therapy, delivered early after stroke on functional recovery
BACKGROUND: Dopamine is a key modulator of striatal function and learning, and may improve motor recovery after stroke. Seven small trials of dopamine agonists after stroke have provided equivocal evidence of the clinical effectiveness of dopamine agonists in improving motor recovery. DESIGN: Dopamine Augmented Rehabilitation in Stroke was a multicentre, randomised, double-blind, placebo-controlled trial with stroke patients randomised to receive 6 weeks of co-careldopa (Sinemet®, Merck Sharp & Dohme Ltd) or placebo in combination with occupational and physical rehabilitation. METHODS: The primary outcome measure was the proportion of patients walking independently at 8 weeks [Rivermead Mobility Index (RMI) score of ≥ 7 points and ‘yes’ to item 7 on the RMI]. Secondary outcome measures assessed physical functioning, pain, cognition, mood, fatigue and carer burden at 8 weeks, 6 months and 12 months. RESULTS: Between May 2011 and March 2014, 593 patients (mean age 68.5 years) and 165 carers (mean age 59.7 years) were recruited from stroke rehabilitation units; 308 patients were randomised to co-careldopa and 285 to placebo at a median of 15 days following stroke onset. The study drug was to be taken 45–60 minutes before therapy, which included motor activities (mean 23.2 and 24.8 sessions in the co-careldopa and placebo groups, respectively). The mean number of investigational medicinal product doses taken was 20.6 in the co-careldopa group and 22.4 in the placebo group. Ability to walk independently was not improved at 8 weeks [40.6% (co-careldopa) vs. 44.6% (placebo); odds ratio 0.78, 95% confidence interval (CI) 0.53 to 1.15], 6 months [51.6% (co-careldopa) vs. 53.3% (placebo)] or 12 months [51.6% (co-careldopa) vs. 56.8% (placebo)]. There were no significant differences for Barthel Index, Nottingham Extended Activities of Daily Living, ABILHAND Manual Ability Measure or Modified Rankin Scale, pain or fatigue at any time point. Montreal Cognitive Assessment scores did not significantly differ; the majority of participants had cognitive impairment at baseline, which improved during 12 months’ follow-up. No difference was observed in General Health Questionnaire 12-item version scores between groups at 8 weeks and 12 months but, at 6 months, those in the co-careldopa group reported significantly better general health [mean difference (MD) –1.33, 95% CI –2.57 to –0.10]. Mortality at 12 months was not significantly different. Carers in the placebo group reported significantly greater burden at 6 months (MD 5.05, 95% CI 0.10 to 10.01) and 12 months (MD 7.52, 95% CI 1.87 to 13.18). CONCLUSION: Co-careldopa in addition to routine NHS occupational and physical therapy is not clinically effective or cost-effective in improving walking, physical functioning, mood or cognition following stroke. We recommend further research to develop imaging and clinical markers that would allow identification of promising drug therapies that would enhance motor therapy in improving walking ability and arm function. Further research is needed to compare strategies of giving drug therapy intermittently immediately prior to therapy sessions or as continuous background daily administration. LIMITATIONS: In total, 10.3% of patients were lost to follow-up at 8 weeks and < 10% of patients met the strict per-protocol definition. Despite this, the findings are robust and generalisable to patients with limited mobility in the first few weeks after stroke. TRIAL REGISTRATION: Current Controlled Trials ISRCTN99643613. FUNDING: This project was funded by the Efficacy and Mechanism Evaluation programme, a Medical Research Council and National Institute for Health Research partnership
New urbanism, crime and the suburbs: a review of the evidence
Sustainability now influences government policy in the UK, Australia and USA and planning policy currently advocates high density, mixed-use residential developments in 'walkable', permeable neighbourhoods, close to public transport, employment and amenities. This clearly demonstrates the growing popularity, influence and application of New Urbanist ideas.This paper reviews the criminological research relating to New Urbanism associated with the three key issues of permeability, rear laneway car parking and mixed-use development. These key issues are discussed from an environmental criminology perspective and challenge New Urbanist assumptions concerning crime. The paper proposes that crime prevention through environmental design (CPTED) and its crime risk assessment model represents a valuable tool for New Urbanists to utilise to reduce opportunities for crime and tackle fear of crime in the community. Recommendations for future research and collaboration are discussed
Beta defensin-2 is reduced in central but not in distal airways of smoker COPD patients
Background: Altered pulmonary defenses in chronic obstructive pulmonary disease (COPD) may promote distal airways bacterial colonization. The expression/activation of Toll Like receptors (TLR) and beta 2 defensin (HBD2) release by epithelial cells crucially affect pulmonary defence mechanisms. Methods: The epithelial expression of TLR4 and of HBD2 was assessed in surgical specimens from current smokers COPD (s-COPD; n = 17), ex-smokers COPD (ex-s-COPD; n = 8), smokers without COPD (S; n = 12), and from non-smoker non-COPD subjects (C; n = 13). Results: In distal airways, s-COPD highly expressed TLR4 and HBD2. In central airways, S and s-COPD showed increased TLR4 expression. Lower HBD2 expression was observed in central airways of s-COPD when compared to S and to ex-s-COPD. s-COPD had a reduced HBD2 gene expression as demonstrated by real-time PCR on micro-dissected bronchial epithelial cells. Furthermore, HBD2 expression positively correlated with FEV1/FVC ratio and inversely correlated with the cigarette smoke exposure. In a bronchial epithelial cell line (16 HBE) IL-1β significantly induced the HBD2 mRNA expression and cigarette smoke extracts significantly counteracted this IL-1 mediated effect reducing both the activation of NFkB pathway and the interaction between NFkB and HBD2 promoter. Conclusions: This study provides new insights on the possible mechanisms involved in the alteration of innate immunity mechanisms in COPD. © 2012 Pace et al
Live to cheat another day: bacterial dormancy facilitates the social exploitation of beta-lactamases
The breakdown of antibiotics by β-lactamases may be cooperative, since resistant cells can detoxify their environment and facilitate the growth of susceptible neighbours. However, previous studies of this phenomenon have used artificial bacterial vectors or engineered bacteria to increase the secretion of β-lactamases from cells. Here, we investigated whether a broad-spectrum β-lactamase gene carried by a naturally occurring plasmid (pCT) is cooperative under a range of conditions. In ordinary batch culture on solid media, there was little or no evidence that resistant bacteria could protect susceptible cells from ampicillin, although resistant colonies could locally detoxify this growth medium. However, when susceptible cells were inoculated at high densities, late-appearing phenotypically susceptible bacteria grew in the vicinity of resistant colonies. We infer that persisters, cells that have survived antibiotics by undergoing a period of dormancy, founded these satellite colonies. The number of persister colonies was positively correlated with the density of resistant colonies and increased as antibiotic concentrations decreased. We argue that detoxification can be cooperative under a limited range of conditions: if the toxins are bacteriostatic rather than bacteridical; or if susceptible cells invade communities after resistant bacteria; or if dormancy allows susceptible cells to avoid bactericides. Resistance and tolerance were previously thought to be independent solutions for surviving antibiotics. Here, we show that these are interacting strategies: the presence of bacteria adopting one solution can have substantial effects on the fitness of their neighbours
Determination of consensus among professionals for community safety terms through a Delphi study
This is a post-peer-review, pre-copyedit version of an article published in Crime Prevention and Community Safety. The definitive publisher-authenticated version 2013, 15(4), pp. 258-277 is available online at: http://dx.doi.org/10.1057/cpcs.2013.9This article reports the findings from a study of Community Safety professionals (Academics, Policymakers and Practitioners), using the Delphi method to determine common definitions, if any, for Community Safety terms in current usage. The study investigated the differences in the way that the terms were used and understood by the members of the three groups. The study was predicated on the view that the groups of Community Safety professionals probably use the language of Community Safety in different ways. It is suggested that work in the field would benefit from a shared terminology, where the same term has the same meaning for different professional groups
CpG DNA modulates interleukin 1β-induced interleukin-8 expression in human bronchial epithelial (16HBE14o-) cells
BACKGROUND: Recognition of repeat unmethylated CpG motifs from bacterial DNA through Toll-like receptor (TLR-9) has been shown to induce interleukin (IL)-8 expression in immune cells. We sought to investigate the role of CpG oligodeoxynucleotides (ODN) on a human bronchial epithelial cells. METHODS: RT-PCR and Western blot analysis were used to determine expression of TLR-9 in human bronchial epithelial cells (16HBE14o-). Cells were treated with CpG ODN in the presence or absence of IL-1β and IL-8 protein was determined using ELISA. In some cases cells were pretreated with chloroquine, an inhibitor of TLR-9 signaling, or SB202190, an inhibitor of the mitogen activated protein kinase p38, prior to treatment with IL-1β and CpG. TLR9 siRNA was used to silence TLR9 prior to treatment with IL-1β and CpG. IκBα and p38 were assessed by Western blot, and EMSA's were performed to determine NF-κB activation. To investigate IL-8 mRNA stability, cells were treated with IL-1β in the absence or presence of CpG for 2 h and actinomycin D was added to induce transcriptional arrest. Cells were harvested at 15 min intervals and Northern blot analysis was performed. RESULTS: TLR-9 is expressed in 16HBE14o- cells. CpG synergistically increased IL-1β-induced IL-8 protein abundance, however treatment with CpG alone had no effect. CpC (a control ODN) had no effect on IL-1β-induced IL-8 levels. In addition, CpG synergistically upregulated TNFα-induced IL-8 expression. Silencing TLR9 using siRNA or pretreatment of cells with chloroquine had little effect on IL-1β-induced IL-8 levels, but abolished CpG-induced synergy. CpG ODN had no effect on NF-κB translocation or DNA binding in 16HBE14o- cells. Treatment with CpG increased phosphorylation of p38 and pretreatment with the p38 inhibitor SB202190 attenuated the synergistic increase in IL-8 protein levels. Analysis of the half-life of IL-8 mRNA revealed that IL-8 mRNA had a longer half-life following the co-treatment of CpG and IL-1β compared to treatment with IL-1β alone. CONCLUSION: Together, these data demonstrate that CpG modulates IL-8 synthesis in the presence of a pro-inflammatory mediator utilizing TLR9 and post-transcriptional mechanisms involving the activation of p38 and stabilization of IL-8 mRNA
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