393 research outputs found

    Vegetative propagation of dieback-tolerant Fraxinus excelsior on

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    book chapterThis publication is based on the work of Action FP1103 FRAXBACK, supported by COST (European Cooperation in Science and Technology)Ash trees which are tolerant to Hymenoscyphus fraxineus may be selected in all age classes among heavily infected populations. They may be produced also by controlled crossings of disease tolerant trees, because the genetic component of inheritance for disease tolerance is high. For mature and juvenile plant material, the deployment of disease tolerant genotypes could be potentially achieved by vegetatively propagating selected genotypes. We describe a system to vegetatively propagate selected ash genotypes and we discuss the prospects and options for using vegetative propagation on all age classes of trees. Mature trees were rejuvenated through the process of micropropagation to establish mother plants in large trays which were cut back repeatedly (hedged) to produce at least two crops of cuttings per year. The rooting capacity of ten genotypes was tested by a commercial nursery over a period of three years, to assess the feasibility of using hedged mother plants for efficient propagation. Commercial practise was to treat cuttings with 0.25% IBA, insert them in plug pots and maintain them covered with fine plastic within low plastic tunnels in a non heated greenhouse and without supplementary heating at the cutting base. In the first year, the mean rooting rate was 53 % for the first crop of cuttings and 35 % for the second. In the second and third years the rooting rates improved to over 80% for each crop of cuttings as experience was gained in handling the material. Rooting rate varied among the genotypes. We assessed the growth and development of micropropagated ash trees in the field from an observation clonal trial, consisting of four mature genotypes which had been established in 2002 in five replicate plots. The micropropagated trees were generally similar in height and dbh to seed derived control trees and developed normally. These observations are discussed in the context of using vegetative propagation as a tool in breeding and for the large scale deployment of ash with tolerance to H. fraxineus.European Cooperation in Science and Technolog

    The spindle assembly checkpoint is satisfied in the absence of interkinetochore tension during mitosis with unreplicated genomes

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    The accuracy of chromosome segregation is enhanced by the spindle assembly checkpoint (SAC). The SAC is thought to monitor two distinct events: attachment of kinetochores to microtubules and the stretch of the centromere between the sister kinetochores that arises only when the chromosome becomes properly bioriented. We examined human cells undergoing mitosis with unreplicated genomes (MUG). Kinetochores in these cells are not paired, which implies that the centromere cannot be stretched; however, cells progress through mitosis. A SAC is present during MUG as cells arrest in response to nocodazole, taxol, or monastrol treatments. Mad2 is recruited to unattached MUG kinetochores and released upon their attachment. In contrast, BubR1 remains on attached kinetochores and exhibits a level of phosphorylation consistent with the inability of MUG spindles to establish normal levels of centromere tension. Thus, kinetochore attachment to microtubules is sufficient to satisfy the SAC even in the absence of interkinetochore tension

    Integrable Deformations of c^=1\hat{c}=1 Strings in Flux Backgrounds

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    We study d=2 0A string theory perturbed by tachyon momentum modes in backgrounds with non-trivial tachyon condensate and Ramond-Ramond (RR) flux. In the matrix model description, we uncover a complexified Toda lattice hierarchy constrained by a pair of novel holomorphic string equations. We solve these constraints in the classical limit for general RR flux and tachyon condensate. Due to the non-holomorphic nature of the tachyon perturbations, the transcendental equations which we derive for the string susceptibility are manifestly non-holomorphic. We explore the phase structure and critical behavior of the theory.Comment: 39 pages, 4 figure

    Extent and distribution of linkage disequilibrium in the Old Order Amish

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    Knowledge of the extent and distribution of linkage disequilibrium (LD) is critical to the design and interpretation of gene mapping studies. Because the demographic history of each population varies and is often not accurately known, it is necessary to empirically evaluate LD on a population-specific basis. Here we present the first genome-wide survey of LD in the Old Order Amish (OOA) of Lancaster County Pennsylvania, a closed population derived from a modest number of founders. Specifically, we present a comparison of LD between OOA individuals and US Utah participants in the International HapMap project (abbreviated CEU) using a high-density single nucleotide polymorphism (SNP) map. Overall, the allele (and haplotype) frequency distributions and LD profiles were remarkably similar between these two populations. For example, the median absolute allele frequency difference for autosomal SNPs was 0.05, with an inter-quartile range of 0.02–0.09, and for autosomal SNPs 10–20 kb apart with common alleles (minor allele frequency≥0.05), the LD measure r 2 was at least 0.8 for 15 and 14% of SNP pairs in the OOA and CEU, respectively. Moreover, tag SNPs selected from the HapMap CEU sample captured a substantial portion of the common variation in the OOA (∼88%) at r 2 ≥0.8. These results suggest that the OOA and CEU may share similar LD profiles for other common but untyped SNPs. Thus, in the context of the common variant-common disease hypothesis, genetic variants discovered in gene mapping studies in the OOA may generalize to other populations. Genet. Epidemiol . 34: 146–150, 2010. © 2009 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64895/1/20444_ftp.pd

    Heterogeneity of Invasive Ductal Carcinoma: Proposal for a Hypothetical Classification

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    To investigate what heterogeneity exists in breast cancer, 228 consecutive patients with operable invasive duetal carcinoma (IDC), not otherwise specified, were categorized on the basis of the horizontal progression model of carcinogenesis. Using the reversed Black's nuclear grade (RBNG) in the IDC component and the association of ductal carcinoma in situ (DCIS), the patients were classified into pure IDC (IDC de novo or ab initio) as Group I, non-high grade (RBNG 1 and 2) IDC with DCIS as Group II, and high grade (RBNG 3) IDC with DCIS as Group III. The Groups classified in the present study appeared as a prognostic factor independent of known prognostic and predictive factors in multivariate test. Group I had the worst prognosis among the three groups and was the most non-responsive to tamoxifen. After performing stratifying analyses by group, it was found that metastasis-free survival was statistically associated with the status of hormone receptors estrogen receptor and progesterone receptor and tamoxifen therapy only in Group II. In addition, the status of c-erbB-2 expression had prognostic significance only within the Group III. Our results may be used to frame an alternative hypothetical model for breast cancer evolution and will lead us to reconsider the tailoring of the comprehensive therapeutic modality used at the present time

    Prevalence and predictors of verbal aggression in a secure mental health service:use of the HCR-20

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    Despite evidence about the negative effects of verbal aggression in mental health wards there is little research about its prevalence or about the factors that predict the behaviour among inpatients. This study aimed to determine the prevalence of verbal aggression in a secure mental health service, and to examine the relationship of verbal aggression with risk factors for aggression in the risk assessment tool HCR-20 in order to establish whether, and with which factors, the behaviour can be predicted. Verbal aggression was measured using the Overt Aggression Scale (OAS) over a 3-month period across a heterogeneous patient group (n = 613). Over half the patients (n = 341, 56%) engaged in 1594 incidents of verbal aggression. The HCR-20 total, clinical, and risk management subscale scores predicted verbal aggression, though effect sizes were not large. Item-outcome analysis revealed that impulsivity, negative attitudes, and non-compliance with medication were the best predictors of verbal aggression and, therefore, should be targeted for intervention. There are key synergies between factors predicting verbal aggression and the core mental health nursing role. Nurses, therefore, are in a prime position to develop and implement interventions that may reduce verbal aggression in mental health inpatients

    KL Estimation of the Power Spectrum Parameters from the Angular Distribution of Galaxies in Early SDSS Data

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    We present measurements of parameters of the 3-dimensional power spectrum of galaxy clustering from 222 square degrees of early imaging data in the Sloan Digital Sky Survey. The projected galaxy distribution on the sky is expanded over a set of Karhunen-Loeve eigenfunctions, which optimize the signal-to-noise ratio in our analysis. A maximum likelihood analysis is used to estimate parameters that set the shape and amplitude of the 3-dimensional power spectrum. Our best estimates are Gamma=0.188 +/- 0.04 and sigma_8L = 0.915 +/- 0.06 (statistical errors only), for a flat Universe with a cosmological constant. We demonstrate that our measurements contain signal from scales at or beyond the peak of the 3D power spectrum. We discuss how the results scale with systematic uncertainties, like the radial selection function. We find that the central values satisfy the analytically estimated scaling relation. We have also explored the effects of evolutionary corrections, various truncations of the KL basis, seeing, sample size and limiting magnitude. We find that the impact of most of these uncertainties stay within the 2-sigma uncertainties of our fiducial result.Comment: Fig 1 postscript problem correcte

    Assessment of health care, hospital admissions, and mortality by ethnicity:population-based cohort study of health-system performance in Scotland

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    Background: Ethnic minorities often experience barriers to health care. We studied six established quality indicators of health-system performance across ethnic groups in Scotland. Methods: In this population-based cohort study, we linked ethnicity from Scotland's Census 2001 (April 29, 2001) to hospital admissions and mortality records, with follow-up until April 30, 2013. Indicators of health-system performance included amenable deaths (ie, deaths avertable by effective treatment), preventable deaths (ie, deaths avertable by public health policy), avoidable deaths (combined amenable and preventable deaths), avoidable hospital admissions, unplanned readmissions, and length of stay. We calculated rate ratios and odds ratios (with 95% CIs) using Poisson and logistic regression, which we multiplied by 100, adjusting first for age-related covariates and then for socioeconomic-related and birthplace-related covariates. The white Scottish population was the reference (rate ratio [RR] 100). Findings: The results are based on 4·61 million people. During the 50·5 million person-years of study, 1·17 million avoidable hospital admissions, 587 740 unplanned readmissions, and 166 245 avoidable deaths occurred. South Asian groups had higher avoidable hospital admissions than the white Scottish group, with the highest reported RRs in Pakistani groups (RR 140·6 [95% CI 131·9–150·0] in men; RR 141·0 [129·0–154·1] in women). There was little variation between ethnic groups in length of stay or unplanned readmission. Preventable and amenable mortality were higher in the white Scottish group than several ethnic minorities including other white British, other white, Indian, and Chinese groups. Such differences were partly diminished by adjustment for socioeconomic status, whereas adjustment for country of birth had little additional effect. Interpretation: These data suggest concerns about the access to and quality of primary care to prevent avoidable hospital admissions, especially for south Asians. Relatively high preventable and amenable deaths in white Scottish people, compared with several ethnic minority populations, were unexpected. Future studies should both corroborate and examine explanations for these patterns. Studies using several indicators simultaneously are also required internationally

    Tinnitus, Suicide, and Suicidal Ideation: A Scoping Review of Primary Research

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    Tinnitus (the perception of sound in the absence of any corresponding external source) is highly prevalent and can be distressing. There are unanswered questions about how tinnitus, suicidal thoughts, and suicidal behaviours co-occur and interact. To establish the extent of scientific literature, this scoping review catalogued primary reports addressing the associations between tinnitus, suicidal ideation, attempted suicide, and death by suicide. We searched OvidSP, Medline, EMBASE, PsycINFO, CINAHL, Google Scholar, EThoS, and ProQuest for all studies and case reports on ideation and/or attempted and/or completed suicide in the context of tinnitus. Twenty-three studies were included, and data were charted according to study type. Several epidemiological and other observational studies gave evidence of risk factors and an association between suicidal ideation, suicidal behaviour, and tinnitus. However, there was no evidence of the direction of causality. Qualitative studies are indicated to explore the patient’s experience and understand the dynamics of any interaction between tinnitus and suicidal thoughts and behaviours. A theory-informed model of tinnitus and suicide needs to be developed to inform the development of interventions and how tinnitus patients are supported clinically
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