666 research outputs found

    Novel micelle PCR-based method for accurate, sensitive and quantitative microbiota profiling

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    In the last decade, many researchers have embraced 16S rRNA gene sequencing techniques, which has led to a wealth of publications and documented differences in the composition of microbial communities derived from many different ecosystems. However, comparison between different microbiota studies is currently very difficult due to the lack of a standardized 16S rRNA gene sequencing protocol. Here we report on a novel approach employing micelle PCR (micPCR) in combination with an internal calibrator that allows for standardization of microbiota profiles via their absolute abundances. The addition of an internal calibrator allows the researcher to express the resulting operational taxonomic units (OTUs) as a measure of 16S rRNA gene copies by correcting the number of sequences of each individual OTU in a sample for efficiency differences in the NGS process. Additionally, accurate quantification of OTUs obtained from negative extraction control samples allows for the subtraction of contaminating bacterial DNA derived from the laboratory environment or chemicals/reagents used. Using equimolar synthetic microbial community samples and low biomass clinical samples, we demonstrate that the calibrated micPCR/NGS methodology possess a much higher precision and a lower limit of detection compared with traditional PCR/NGS, resulting in more accurate microbiota profiles suitable for multi-study comparison

    Micelle PCR reduces chimera formation in 16S rRNA profiling of complex microbial DNA mixtures

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    16S rRNA gene profiling has revolutionized the field of microbial ecology. Many researchers in various fields have embraced this technology to investigate bacterial compositions of samples derived from many different ecosystems. However, it is important to acknowledge the current limitations and drawbacks of 16S rRNA gene profiling. Although sample handling, DNA extraction methods and the choice of universal 16S rRNA gene PCR primers are well known factors that could seriously affect the final results of microbiota profiling studies, inevitable amplification artifacts, such as chimera formation and PCR competition, are seldom appreciated. Here we report on a novel micelle based amplification strategy, which overcomes these limitations via the clonal amplification of targeted DNA molecules. Our results show that micelle PCR drastically reduces chimera formation by a factor of 38 (1.5% vs. 56.9%) compared with traditional PCR, resulting in improved microbial diversity estimates. In addition, compartmentalization during micelle PCR prevents PCR competition due to unequal amplification rates of different 16S template molecules, generating robust and accurate 16S microbiota profiles required for comparative studies (e.g. longitudinal surveys)

    Interventions for families with multiple problems:Similar contents but divergent formats

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    For families with multiple problems (FMP), knowledge is lacking on the practice elements of interventions (the distinct techniques practitioners use to promote positive outcomes) and their program elements (intervention design and delivery systems). The aim of this study is to identify both common and specific practice and program elements so as to determine contents and overlap between interventions. For FMP, we selected interventions that had at least moderate (>0.5) effect sizes in the Dutch context (N = 8). A deductive content analysis was used to assess the manuals of these interventions with the taxonomy of interventions for FMP. We defined as common those elements found in at least five of the eight interventions and as specific those found in fewer than five. Of the practice elements, 79% were common across the interventions, and 21% were intervention specific. Interventions with the highest percentages of intervention-specific elements derived from the taxonomy were 10 for the Future (15%), Family Central (14%), Intensive Family Therapy (14%), and Multisystemic therapy (11%). Core program elements: duration, intensity, intervision, supervision, and consultation, varied greatly between interventions. Among interventions for FMP, we found practice elements to have considerable overlap. Among program elements, we found greater variety

    Elucidating care for families with multiple problems in routine practice: Self-registered practice and program elements of practitioners

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    Contains fulltext : 217617.pdf (publisher's version ) (Open Access)Families with multiple problems (FMP), also defined as multiproblem families or multistressed families, face multiple, severe, chronic and intertwined problems in different areas of life. Content and provision of interventions targeting FMP in routine practice may largely deviate from guidelines in intervention manuals. The aim of this study was to identify practice and program elements provided to FMP in routine practice, including the intensity, manner of provision, and recipients, per intervention phase (starting-, care- and end phase). We selected interventions with at least moderate (d >= 0.5) effect sizes in the Dutch context, yielding eight interventions. Practitioners of 26 Dutch organizations systematically registered information on practice and program elements, intensity, manner of provision, and recipients, using the taxonomy of interventions for FMP. Within 474 trajectories we found that elements regarding activation of the social network of FMP were provided least often (in less than 48-77% of the families). Elements were provided mainly through psycho-education (25-33%) and instruction (21-24%). Interventions focused more on parents (53-62%) than on children (26-32%). Program elements hardly changed between phases of interventions, although the number of visits decreased (from an average of six visits a month during the starting phase to four visits during the end phase). An inventory of elements that make part of interventions for FMP allows studying the effectiveness of these interventions in a more detailed way. This yields information that may help to identify the optimal sequence, intensity and duration of elements and enables to better understand outcomes of interventions for FMP.10 p

    Adolescents' use of care for behavioral and emotional problems: Types, trends, and determinants

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    Objective: While adolescents use various types of care for behavioral and emotional problems, evidence on age trends and determinants per type is scarce. We aimed to assess use of care by adolescents because of behavioral and emotional problems, overall and by type, and its determinants, for ages 10-19 years. Methods: We obtained longitudinal data on 2,230 adolescents during ages 10-19 from four measurements regarding use of general care and specialized care (youth social care and mental healthcare) in the preceding 6 months, the Child Behavior Checklist (CBCL) and Youth Self-Report, and child and family characteristics. We analyzed data by multilevel logistic regression. Results: Overall rates of use increased from 20.1% at age 10/11 to 32.2% at age 19: general care was used most. At age 10/11 use was higher among boys, at age 19 among girls. Use of general care increased for both genders, whereas use of specialized care increased among girls but decreased among boys. This differential change was associated with CBCL externalizing and internalizing problems, school problems, family socioeconomic status, and parental divorce. Preceding CBCL problems predicted more use: most for mental health care and least for general care. Moreover, general care was used more frequently by low and medium socioeconomic status families, with odds ratios (95%-confidence intervals): 1.52 (1.23;1.88) and 1.40 (1.17;1.67); youth social care in case of parental divorce, 2.07 (1.36;3.17); and of special education, 2.66 (1.78;3.95); and mental healthcare in case of special education, 2.66 (1.60;4.51). Discussion: Adolescents with behavioral and emotional problems use general care most frequently. Overall use increases with age. Determinants of use vary per type

    Brain-derived neurotrophic factor signaling in the HVC is required for testosterone-induced song of female canaries

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    Testosterone-induced singing in songbirds is thought to involve testosterone-dependent morphological changes that include angiogenesis and neuronal recruitment into the HVC, a central part of the song control circuit. Previous work showed that testosterone induces the production of vascular endothelial growth factor (VEGF) and its receptor (VEGFR2 tyrosine kinase), which in turn leads to an upregulation of brain-derived neurotrophic factor (BDNF) production in HVC endothelial cells. Here we report for the first time that systemic inhibition of the VEGFR2 tyrosine kinase is sufficient to block testosterone-induced song in adult female canaries, despite sustained androgen exposure and the persistence of the effects of testosterone on HVC morphology. Expression of exogenous BDNF in HVC, induced locally by in situ transfection, reversed the VEGFR2 inhibition-mediated blockade of song development, thereby restoring the behavioral phenotype associated with androgen-induced song. The VEGFR2-inhibited, BDNF-treated females developed elaborate malelike song that included large syllable repertoires and high syllable repetition rates, features known to attract females. Importantly, although functionally competent new neurons were recruited to HVC after testosterone treatment, the time course of neuronal addition appeared to follow BDNF-induced song development. These findings indicate that testosterone-associated VEGFR2 activity is required for androgen-induced song in adult songbirds and that the behavioral effects of VEGFR2 inhibition can be rescued by BDNF within the adult HVC. Copyright © 2009 Society for Neuroscience

    Medezeggenschap in faillissement: ook een adviesrecht voor de cliëntenraad?

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    De centrale vraag is of de cliëntenraad van een zorginstelling adviesrecht heeft in faillissement en of het wenselijk is het adviesrecht in faillissement wettelijk vast te leggen. Deze vraag wordt beantwoord door een vergelijking te maken met het adviesrecht van de ondernemingsraad in faillissement. Auteurs concluderen dat het wenselijk is dat de cliëntenraad adviesrecht heeft, onder meer omdat de WOR (ondernemingsraad) en Wmcz (cliëntenraad) hetzelfde doel hebben, het faillissement van een zorginstelling ingrijpende gevolgen kan hebben voor cliënten en het adviesrecht van de cliëntenraad van belang is voor de curator. Aanbevolen wordt het adviesrecht in faillissement te verankeren in de Wmcz

    A log analysis study of 10 years of ebook consumption in academic library collections

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    Even though libraries have been offering eBooks for more than a decade, very little is known about eBook access and consumption in academic library collections. This paper addresses this gap with a log analysis study of eBook access at the library of the University of Waikato. This in-depth analysis covers a period spanning 10 years of eBook use at this university. We draw conclusions about the use of eBooks at this institution and compare the results with other published studies of eBook usage at tertiary institutes
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