551 research outputs found
Natural revegetation of placer mined lands of interior Alaska II
To the uninitiated eye an aerial photo of Fairbanks’ surrounding area includes patches of what might appear to be the channels left by the workings of a bark beetle grub. These series of parallel mounds with sequences of smaller undulations on their surfaces are actually composed of coarse gravel and are the product of some forty years of gold dredging. Started in 1928, dredging was concentrated in several of the tributary valleys of the Tanana River and Goldstream Creek. Some of these tailings piles support lush growth while others are relatively bare. At present, no ecologically oriented studies, either qualitative or quantitative, have been published concerning the gold dredge tailings. It was therefore the intent of this study to obtain a broad picture of the present stage of revegetation, in order that further ecological work and, hopefully, assisted rehabilitation may be facilitated.Introduction -- Methods -- Preliminary results -- Stands with little vegetation -- Intermediate stands -- Well developed stands -- Concluding remarks
Genomic variations associated with attenuation in Mycobacterium avium subsp paratuberculosis vaccine strains
BACKGROUND: Mycobacterium avium subspecies paratuberculosis (MAP) whole cell vaccines have been widely used tools in the control of Johne's disease in animals despite being unable to provide complete protection. Current vaccine strains derive from stocks created many decades ago; however their genotypes, underlying mechanisms and relative degree of their attenuation are largely unknown.
RESULTS: Using mouse virulence studies we confirm that MAP vaccine strains 316 F, II and 2e have diverse but clearly attenuated survival and persistence characteristics compared with wild type strains. Using a pan genomic microarray we characterise the genomic variations in a panel of vaccine strains sourced from stocks spanning over 40 years of maintenance. We describe multiple genomic variations specific for individual vaccine stocks in both deletion (26-32 Kbp) and tandem duplicated (11-40 Kbp) large variable genomic islands and insertion sequence copy numbers. We show individual differences suitable for diagnostic differentiation between vaccine and wild type genotypes and provide evidence for functionality of some of the deleted MAP-specific genes and their possible relation to attenuation.
CONCLUSIONS: This study shows how culture environments have influenced MAP genome diversity resulting in large tandem genomic duplications, deletions and transposable element activity. In combination with classical selective systematic subculture this has led to fixation of specific MAP genomic alterations in some vaccine strain lineages which link the resulting attenuated phenotypes with deficiencies in high reactive oxygen species handling
Enhancing Social-Emotional Health and Wellbeing in the Early Years (E-SEE): A study protocol of a community-based randomised controlled trial with process and economic evaluations of the incredible years infant and toddler parenting programmes, delivered in a proportionate universal model
This is the final version. Available from the publisher via the DOI in this record.Introduction: Behavioural and mental disorders have become a public health crisis and by 2020 may surpass physical illness as a major cause of disability. Early prevention is key. Two Incredible Years (IY) parent programmes that aim to enhance child well-being and development, IY Infant and IY Toddler, will be delivered and evaluated in a proportionate universal intervention model called Enhancing Social-Emotional Health and Wellbeing in the Early Years (E-SEE) Steps. The main research question is: Does E-SEE Steps enhance child social emotional well-being at 20 months when compared with services as usual? Methods and analysis: E-SEE Steps will be delivered in community settings by Early Years Children's Services and/or Public Health staff across local authorities. Parents of children aged 8 weeks or less, identified by health visitors, children's centre staff or self-referral, are eligible for participation in the trial. The randomisation allocation ratio is 5:1 (intervention to control). All intervention parents will receive an Incredible Years Infant book (universal level), and may be offered the Infant and/or Toddler group-based programme/s - based on parent depression scores on the Patient Health Questionnaire or child social emotional well-being scores on the Ages and Stages Questionnaire: Social Emotional, Second Edition (ASQ:SE-2). Control group parents will receive services as usual. A process and economic evaluation are included. The primary outcome for the study is social emotional well-being, assessed at 20 months, using the ASQ:SE-2. Intention-to-treat and per protocol analyses will be conducted. Clustering and hierarchical effects will be accounted for using linear mixed models. Ethics and dissemination: Ethical approvals have been obtained from the University of York Education Ethics Committee (ref: FC15/03, 10 August 2015) and UK NHS REC 5 (ref: 15/WA/0178, 22 May 2015. The current protocol is Version 9, 26 February 2018. The sponsor of the trial is the University of York. Dissemination of findings will be via peer-reviewed journals, conference presentations and public events.National Institute for Health Research (NIHR
Altered Outer Retinal Structure, Electrophysiology and Visual Perception in Parkinson\u27s Disease.
BACKGROUND: Visual biomarkers of Parkinson\u27s disease (PD) are attractive as the retina is an outpouching of the brain. Although inner retinal neurodegeneration in PD is well-established this has overlap with other neurodegenerative diseases and thus outer retinal (photoreceptor) measures warrant further investigation.
OBJECTIVE: To examine in a cross-sectional study whether clinically implementable measures targeting outer retinal function and structure can differentiate PD from healthy ageing and whether these are sensitive to intraday levodopa (L-DOPA) dosing.
METHODS: Centre-surround perceptual contrast suppression, macular visual field sensitivity, colour discrimination, light-adapted electroretinography and optical coherence tomography (OCT) were tested in PD participants (n = 16) and controls (n = 21). Electroretinography and OCT were conducted before and after midday L-DOPA in PD participants, or repeated after ∼2 hours in controls.
RESULTS: PD participants had decreased center-surround contrast suppression (p \u3c 0.01), reduced macular visual field sensitivity (p \u3c 0.05), color vision impairment (p \u3c 0.01) photoreceptor dysfunction (a-wave, p \u3c 0.01) and photoreceptor neurodegeneration (outer nuclear layer thinning, p \u3c 0.05), relative to controls. Effect size comparison between inner and outer retinal parameters showed that photoreceptor metrics were similarly robust in differentiating the PD group from age-matched controls as inner retinal changes. Electroretinography and OCT were unaffected by L-DOPA treatment or time.
CONCLUSIONS: We show that outer retinal outcomes of photoreceptoral dysfunction (decreased cone function and impaired color vision) and degeneration (i.e., outer nuclear layer thinning) were equivalent to inner retinal metrics at differentiating PD from healthy age-matched adults. These findings suggest outer retinal metrics may serve as useful biomarkers for PD
Gastrointestinal perforation in metastatic colorectal cancer patients with peritoneal metastases receiving bevacizumab
Published online: May 7, 2015Aim: To investigate the safety and efficacy of adding bevacizumab to first-line chemotherapy in metastatic colorectal cancer patients with peritoneal disease. Methods: We compared rates of gastrointestinal perforation in patients with metastatic colorectal cancer and peritoneal disease receiving first-line chemotherapy with and without bevacizumab in three distinct cohorts: (1) the AGITG MAX trial (Phase III randomised clinical trial comparing capecitabine vs capecitabine and bevacizumab vs capecitabine, bevacizumab and mitomycinC); (2) the prospective Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) registry (any first-line regimen ± bevacizumab); and (3) two cancer centres in New South Wales, Australia [Macarthur Cancer Therapy Centre and Liverpool Cancer Therapy Centre (NSWCC) from January 2005 to Decenber 2012, (any first-line regimen ± bevacizumab). For the AGITG MAX trial capecitabine was compared to the other two arms (capecitabine/bevacizumab and capecitabine/bevacizumab/mitomycinC). In the AGITG MAX trial and the TRACC registry rates of gastrointestinal perforation were also collected in patients who did not have peritoneal metastases. Secondary endpoints included progression-free survival, chemotherapy duration, and overall survival. Time-to-event outcomes were estimated using the Kaplan-Meier method and compared using the log-rank test. Results: Eighty-four MAX, 179 TRACC and 69 NSWCC patients had peritoneal disease. There were no gastrointestinal perforations recorded in either the MAX subgroup or the NSWCC cohorts. Of the patients without peritoneal disease in the MAX trial, 4/300 (1.3%) in the bevacizumab arms had gastrointestinal perforations compared to 1/123 (0.8%) in the capecitabine alone arm. In the TRACC registry 3/126 (2.4%) patients who had received bevacizumab had a gastrointestinal perforation compared to 1/53 (1.9%) in the chemotherapy alone arm. In a further analysis of patients without peritoneal metastases in the TRACC registry, the rate of gastrointestinal perforations was 9/369 (2.4%) in the chemotherapy/bevacizumab group and 5/177 (2.8%) in the chemotherapy alone group. The addition of bevacizumab to chemotherapy was associated with improved progression-free survival in all three cohorts: MAX 6.9 m vs 4.9 m, HR = 0.64 (95%CI: 0.42-1.02); P = 0.063; TRACC 9.1 m vs 5.5 m, HR = 0.61 (95%CI: 0.37-0.86); P = 0.009; NSWCC 8.7 m vs 6.8 m, HR = 0.75 (95%CI: 0.43-1.32); P = 0.32. Chemotherapy duration was similar across the groups. Conclusion: Patients with peritoneal disease do not appear to have an increased risk of gastrointestinal perforations when receiving first-line therapy with bevacizumab compared to systemic therapy alone.Aflah Roohullah, Hui-Li Wong, Katrin M Sjoquist, Peter Gibbs, Kathryn Field, Ben Tran, Jeremy Shapiro, Joe Mckendrick, Desmond Yip, Louise Nott, Val Gebski, Weng Ng, Wei Chua, Timothy Price, Niall Tebbutt, Lorraine Chantril
Determining the Composition of the Vacuum-Liquid Interface in Ionic-Liquid Mixtures
The vacuum-liquid interfaces of a number of ionic-liquid mixtures have been investigated using a combination of reactive-atom scattering with laser-induced fluorescence detection (RAS-LIF), selected surface tension measurements, and molecular dynamics (MD) simulations. The mixtures are based on the widespread 1-alkyl-3-methylimidazolium ([Cnmim]+) cation, including mixed cations which differ in chain length or chemical functionality with a common anion; and different anions for a common cation. RAS-LIF results imply that the surface compositions exhibit a general form of non-stoichiometric behaviour that mimics the well-known Henry’s and Raoult’s laws at low and high mole fraction, respectively. The Extended Langmuir model provides a moderately good single-parameter fit, but higher-order terms are required for an accurate description. The quantitative relationship between RAS-LIF and surface tension, which probes the surface composition only indirectly, is explored for mixtures of [C2mim]+ and [C12mim]+ with a common bis(trifluoromethylsulfonyl)imide ([NTf2]-) anion. Extended Langmuir model fits to surface tension data are broadly consistent with those to RAS-LIF; however, several other common approaches to extracting surface compositions from measured surface tensions result in much larger discrepancies. MD simulations suggest that RAS-LIF faithfully reports on the alkyl-chain exposure at the surface, which is only subtly modified by composition-dependent structural reorganisation
Pharmacoeconomic analysis of adjuvant oral capecitabine vs intravenous 5-FU/LV in Dukes' C colon cancer: the X-ACT trial
Oral capecitabine (Xeloda<sup>®</sup>) is an effective drug with favourable safety in adjuvant and metastatic colorectal cancer. Oxaliplatin-based therapy is becoming standard for Dukes' C colon cancer in patients suitable for combination therapy, but is not yet approved by the UK National Institute for Health and Clinical Excellence (NICE) in the adjuvant setting. Adjuvant capecitabine is at least as effective as 5-fluorouracil/leucovorin (5-FU/LV), with significant superiority in relapse-free survival and a trend towards improved disease-free and overall survival. We assessed the cost-effectiveness of adjuvant capecitabine from payer (UK National Health Service (NHS)) and societal perspectives. We used clinical trial data and published sources to estimate incremental direct and societal costs and gains in quality-adjusted life months (QALMs). Acquisition costs were higher for capecitabine than 5-FU/LV, but higher 5-FU/LV administration costs resulted in 57% lower chemotherapy costs for capecitabine. Capecitabine vs 5-FU/LV-associated adverse events required fewer medications and hospitalisations (cost savings £3653). Societal costs, including patient travel/time costs, were reduced by >75% with capecitabine vs 5-FU/LV (cost savings £1318), with lifetime gain in QALMs of 9 months. Medical resource utilisation is significantly decreased with capecitabine vs 5-FU/LV, with cost savings to the NHS and society. Capecitabine is also projected to increase life expectancy vs 5-FU/LV. Cost savings and better outcomes make capecitabine a preferred adjuvant therapy for Dukes' C colon cancer. This pharmacoeconomic analysis strongly supports replacing 5-FU/LV with capecitabine in the adjuvant treatment of colon cancer in the UK
Reactive-Atom Scattering from Liquid Crystals at the Liquid-Vacuum Interface : [C12mim][BF4] and 4-Cyano-4′-Octylbiphenyl (8CB)
Two complementary approaches were used to study the liquid-vacuum interface of the liquid-crystalline ionic liquid 1-dodecyl-3-methylimidazolium tetrafluoroborate ([C12mim][BF4]) in the smectic A (SmA) and isotropic phases. O atoms with two distinct incident translational energies were scattered from the surface of [C12mim][BF4]. Angle-dependent time-of-flight distributions and OH yields, respectively, were recorded from high- and low-energy O atoms. There were no significant changes in the measurements using either approach, nor the properties derived from them, accompanying the transition from the SmA to the isotropic phase. This indicates that the surface structure of [C12mim][BF4] remains essentially unchanged across the phase boundary, implying that the bulk order and surface structure are not strongly correlated for this material. This effect is ascribed to the strong propensity for the outer surfaces of ionic liquids to be dominated by alkyl chains, over an underlying layer rich in anions and cation head groups, whether or not the bulk material is a liquid crystal. In a comparative study, the OH yield from the surface of the liquid crystal, 8CB, was found to be affected by the bulk order, showing a surprising step increase at the SmA-nematic transition temperature, whose origin is the subject of speculation
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