613 research outputs found

    FEED CONDITIONING EFFECTS ON ENZYMES, AMINO ACIDS, AND SUBSEQUENT BROILER PERFORMANCE

    Get PDF
    There are many things that can be done to improve broiler performance including, but not limited to, pelleting, proper Lys inclusion, and exogenous enzyme supplementation. Pelleting has the ability to improve feed form, reduce wastage, improve bird performance metrics, and decrease pathogens within the feed. Pathogen reduction can be further reduced by hygienic pelleting practices which include an increase in temperature or retention time within a conditioner or hygieniser. However, hygienic pelleting can degrade valuable AA and enzymes (more specifically for the current thesis research Lys and phytase) and make them unavailable to the animal. Supplementing Lys to account for the loss can increase the price of feed production but can be balanced by the improvement in broiler LWG. Performing research on novel phytases to improve enzyme activity after the addition of heat and within the digestive tract of the bird critical in order to improve bird performance metrics. Evaluating high conditioning temperature and exposure time within the pelleting process (hygienic pelleting) in diets that vary in digestible lysine and corresponding amino acid ratio on Ross 708 starter broiler performance, amino acid digestibility, and requirement is the purpose of the initial study. A 5 x 2 factorial arrangement of treatments with 5 levels of digestible lysine (- 20%, -10%, 2019 Ross Broiler Starter Nutrition recommendation, +10%, and +20%) and 2 degrees of pelleting (Standard and Hygienic) was utilized in a randomized complete block design. Each treatment was fed to 12 replicate pens of 10 male broiler Hubbard x Ross 708 chicks for a 21-day period. On the morning following day 7, 14 and 21, birds and feed were weighed by pen for performance calculations and ileal contents were collected on d22 for AA digestibility calculations. Standard Pelleting and Hygienic Pelleting demonstrated a 1.19 and 1.37% Lys requirement, respectively, using the broken-line regression model. Performance data and the broken-line regression model suggest an approximate 10% increase in Lys and corresponding amino acid ratio relative to 2019 Ross Broiler Starter Nutrition Specifications for Hygienic Pelleting to provide optimal live weight gain. Hygienic Pelleting decreased amino acid digestibility and increased subsequent FCR when diets were formulated to decreased amino acid density. The assessment of novel exogenous phytase enzymes that can be added to the mixer prior to pelleting is important for the continual improvement of global broiler production. Two experiments were conducted to determine in vitro activity post pelleting and in vivo efficacy post feeding of a novel phytase. The objective of the first study was to determine activity and retention of a novel phytase enzyme (CJ Phytase) and a commercially available phytase (Quantum Blue 5G®) at different 30 second conditioning temperatures (75, 80, 85, and 90˚C) post-pelleting. The objective of the second study was to determine the effects of these phytase sources conditioned for 30 seconds at the 75˚C conditioning temperature on broiler performance, bone mineralization, and mineral digestibility. Experiment one consisted of a 2 (phytase source) x 4 (conditioning temperature) factorial arrangement. A conditioning temperature main effect (P=0.0003) demonstrated that activity of both phytase products decreased at 85˚C and decreased again at 90˚C. In experiment two, 2,304 Hubbard x Ross 708 birds were obtained and fed one of eight diets for a 42-day period. Diets included Positive Control, Negative Control deficient in calcium and Available P by 0.2%, and graded levels of NC+ CJ Phytase (250, 500, 1,000, 1,500, and 3,000 FTU/kg). In order to provide a commercially available comparison, an NC + Quantum Blue 5G 500 FTU/kg was also fed. All phytase additions increased AID P, d42 tibia ash percentage, and d0-42 LWG relative to the NC diet (

    The COMET (Comparison of Operative versus Monitoring and Endocrine Therapy) trial: a phase III randomised controlled clinical trial for low-risk ductal carcinoma in situ (DCIS)

    Get PDF
    Introduction Ductal carcinoma in situ (DCIS) is a noninvasive non-obligate precursor of invasive breast cancer. With guideline concordant care (GCC), DCIS outcomes are at least as favourable as some other early stage cancer types such as prostate cancer, for which active surveillance (AS) is a standard of care option. However, AS has not yet been tested in relation to DCIS. The goal of the COMET (Comparison of Operative versus Monitoring and Endocrine Therapy) trial for low-risk DCIS is to gather evidence to help future patients consider the range of treatment choices for low-risk DCIS, from standard therapies to AS. The trial will determine whether there may be some women who do not substantially benefit from current GCC and who could thus be safely managed with AS. This protocol is version 5 (11 July 2018). Any future protocol amendments will be submitted to Quorum Centralised Institutional Review Board/local institutional review boards for approval via the sponsor of the study (Alliance Foundation Trials). Methods and analysis COMET is a phase III, randomised controlled clinical trial for patients with low-risk DCIS. The primary outcome is ipsilateral invasive breast cancer rate in women undergoing GCC compared with AS. Secondary objectives will be to compare surgical, oncological and patient-reported outcomes. Patients randomised to the GCC group will undergo surgery as well as radiotherapy when appropriate; those in the AS group will be monitored closely with surgery only on identification of invasive breast cancer. Patients in both the GCC and AS groups will have the option of endocrine therapy. The total planned accrual goal is 1200 patients. Ethics and dissemination The COMET trial will be subject to biannual formal review at the Alliance Foundation Data Safety Monitoring Board meetings. Interim analyses for futility/safety will be completed annually, with reporting following Consolidated Standards of Reporting Trials (CONSORT) guidelines for noninferiority trials

    Towards establishing consistency in triage in a tertiary specialty

    Get PDF
    Clinical Genetics services provide a diagnostic, counselling and genetic testing service for children and adults affected by, or at risk of, a genetic condition, most of which are rare, and/or genetically heterogeneous. Appropriate triage of referrals is crucial to ensure that the most urgent referrals are seen as quickly as possible, without negatively impacting the waiting times of less urgent cases. We aimed to examine triage practice in six Clinical Genetic centres across the United Kingdom and Ireland. Thirteen simulated referrals were drafted based on common referrals to Clinical Genetics. Copies of each referral were forwarded to each centre, where 10 nominated clinicians were asked to triage each referral. Triaged referrals were returned to the coordinating author for analysis. An electronic questionnaire was contemporaneously completed by clinical leads in each unit to gather local demographic details and local operating procedures relevant to triage. Widespread inconsistencies were noted both within and between units, with respect to the acceptance of referrals to the services, prioritisation and designated clinic type. Referral rates, staffing levels and waiting lists varied widely between units. Inconsistencies observed between units are likely influenced by a number of factors, including staffing levels, referral rates and average family size. Inconsistency within units likely reflects the complex nature of many Clinical Genetic referrals, and triage guidelines should help improve decision-making in this setting

    Genomic analyses in Cornelia de Lange Syndrome and related diagnoses: Novel candidate genes, <scp>genotype–phenotype</scp> correlations and common mechanisms

    Get PDF
    Cornelia de Lange Syndrome (CdLS) is a rare, dominantly inherited multisystem developmental disorder characterized by highly variable manifestations of growth and developmental delays, upper limb involvement, hypertrichosis, cardiac, gastrointestinal, craniofacial, and other systemic features. Pathogenic variants in genes encoding cohesin complex structural subunits and regulatory proteins (NIPBL, SMC1A, SMC3, HDAC8, and RAD21) are the major pathogenic contributors to CdLS. Heterozygous or hemizygous variants in the genes encoding these five proteins have been found to be contributory to CdLS, with variants in NIPBL accounting for the majority (&gt;60%) of cases, and the only gene identified to date that results in the severe or classic form of CdLS when mutated. Pathogenic variants in cohesin genes other than NIPBL tend to result in a less severe phenotype. Causative variants in additional genes, such as ANKRD11, EP300, AFF4, TAF1, and BRD4, can cause a CdLS‐like phenotype. The common role that these genes, and others, play as critical regulators of developmental transcriptional control has led to the conditions they cause being referred to as disorders of transcriptional regulation (or “DTRs”). Here, we report the results of a comprehensive molecular analysis in a cohort of 716 probands with typical and atypical CdLS in order to delineate the genetic contribution of causative variants in cohesin complex genes as well as novel candidate genes, genotype–phenotype correlations, and the utility of genome sequencing in understanding the mutational landscape in this population

    BHPR research: qualitative1. Complex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis

    Get PDF
    Background: Foot surgery is common in patients with RA but research into surgical outcomes is limited and conceptually flawed as current outcome measures lack face validity: to date no one has asked patients what is important to them. This study aimed to determine which factors are important to patients when evaluating the success of foot surgery in RA Methods: Semi structured interviews of RA patients who had undergone foot surgery were conducted and transcribed verbatim. Thematic analysis of interviews was conducted to explore issues that were important to patients. Results: 11 RA patients (9 ♂, mean age 59, dis dur = 22yrs, mean of 3 yrs post op) with mixed experiences of foot surgery were interviewed. Patients interpreted outcome in respect to a multitude of factors, frequently positive change in one aspect contrasted with negative opinions about another. Overall, four major themes emerged. Function: Functional ability & participation in valued activities were very important to patients. Walking ability was a key concern but patients interpreted levels of activity in light of other aspects of their disease, reflecting on change in functional ability more than overall level. Positive feelings of improved mobility were often moderated by negative self perception ("I mean, I still walk like a waddling duck”). Appearance: Appearance was important to almost all patients but perhaps the most complex theme of all. Physical appearance, foot shape, and footwear were closely interlinked, yet patients saw these as distinct separate concepts. Patients need to legitimize these feelings was clear and they frequently entered into a defensive repertoire ("it's not cosmetic surgery; it's something that's more important than that, you know?”). Clinician opinion: Surgeons' post operative evaluation of the procedure was very influential. The impact of this appraisal continued to affect patients' lasting impression irrespective of how the outcome compared to their initial goals ("when he'd done it ... he said that hasn't worked as good as he'd wanted to ... but the pain has gone”). Pain: Whilst pain was important to almost all patients, it appeared to be less important than the other themes. Pain was predominately raised when it influenced other themes, such as function; many still felt the need to legitimize their foot pain in order for health professionals to take it seriously ("in the end I went to my GP because it had happened a few times and I went to an orthopaedic surgeon who was quite dismissive of it, it was like what are you complaining about”). Conclusions: Patients interpret the outcome of foot surgery using a multitude of interrelated factors, particularly functional ability, appearance and surgeons' appraisal of the procedure. While pain was often noted, this appeared less important than other factors in the overall outcome of the surgery. Future research into foot surgery should incorporate the complexity of how patients determine their outcome Disclosure statement: All authors have declared no conflicts of interes

    The NANOGrav 15-year Data Set: Search for Anisotropy in the Gravitational-Wave Background

    Full text link
    The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has reported evidence for the presence of an isotropic nanohertz gravitational wave background (GWB) in its 15 yr dataset. However, if the GWB is produced by a population of inspiraling supermassive black hole binary (SMBHB) systems, then the background is predicted to be anisotropic, depending on the distribution of these systems in the local Universe and the statistical properties of the SMBHB population. In this work, we search for anisotropy in the GWB using multiple methods and bases to describe the distribution of the GWB power on the sky. We do not find significant evidence of anisotropy, and place a Bayesian 95%95\% upper limit on the level of broadband anisotropy such that (Cl>0/Cl=0)<20%(C_{l>0} / C_{l=0}) < 20\%. We also derive conservative estimates on the anisotropy expected from a random distribution of SMBHB systems using astrophysical simulations conditioned on the isotropic GWB inferred in the 15-yr dataset, and show that this dataset has sufficient sensitivity to probe a large fraction of the predicted level of anisotropy. We end by highlighting the opportunities and challenges in searching for anisotropy in pulsar timing array data.Comment: 19 pages, 11 figures; submitted to Astrophysical Journal Letters as part of Focus on NANOGrav's 15-year Data Set and the Gravitational Wave Background. For questions or comments, please email [email protected]

    The NANOGrav 15-Year Data Set: Detector Characterization and Noise Budget

    Get PDF
    Pulsar timing arrays (PTAs) are galactic-scale gravitational wave detectors. Each individual arm, composed of a millisecond pulsar, a radio telescope, and a kiloparsecs-long path, differs in its properties but, in aggregate, can be used to extract low-frequency gravitational wave (GW) signals. We present a noise and sensitivity analysis to accompany the NANOGrav 15-year data release and associated papers, along with an in-depth introduction to PTA noise models. As a first step in our analysis, we characterize each individual pulsar data set with three types of white noise parameters and two red noise parameters. These parameters, along with the timing model and, particularly, a piecewise-constant model for the time-variable dispersion measure, determine the sensitivity curve over the low-frequency GW band we are searching. We tabulate information for all of the pulsars in this data release and present some representative sensitivity curves. We then combine the individual pulsar sensitivities using a signal-to-noise-ratio statistic to calculate the global sensitivity of the PTA to a stochastic background of GWs, obtaining a minimum noise characteristic strain of 7×10157\times 10^{-15} at 5 nHz. A power law-integrated analysis shows rough agreement with the amplitudes recovered in NANOGrav's 15-year GW background analysis. While our phenomenological noise model does not model all known physical effects explicitly, it provides an accurate characterization of the noise in the data while preserving sensitivity to multiple classes of GW signals.Comment: 67 pages, 73 figures, 3 tables; published in Astrophysical Journal Letters as part of Focus on NANOGrav's 15-year Data Set and the Gravitational Wave Background. For questions or comments, please email [email protected]

    The NANOGrav 15-year Data Set: Bayesian Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries

    Get PDF
    Evidence for a low-frequency stochastic gravitational wave background has recently been reported based on analyses of pulsar timing array data. The most likely source of such a background is a population of supermassive black hole binaries, the loudest of which may be individually detected in these datasets. Here we present the search for individual supermassive black hole binaries in the NANOGrav 15-year dataset. We introduce several new techniques, which enhance the efficiency and modeling accuracy of the analysis. The search uncovered weak evidence for two candidate signals, one with a gravitational-wave frequency of \sim4 nHz, and another at \sim170 nHz. The significance of the low-frequency candidate was greatly diminished when Hellings-Downs correlations were included in the background model. The high-frequency candidate was discounted due to the lack of a plausible host galaxy, the unlikely astrophysical prior odds of finding such a source, and since most of its support comes from a single pulsar with a commensurate binary period. Finding no compelling evidence for signals from individual binary systems, we place upper limits on the strain amplitude of gravitational waves emitted by such systems.Comment: 23 pages, 13 figures, 2 tables. Accepted for publication in Astrophysical Journal Letters as part of Focus on NANOGrav's 15-year Data Set and the Gravitational Wave Background. For questions or comments, please email [email protected]

    The NANOGrav 15 yr Data Set: Search for Transverse Polarization Modes in the Gravitational-wave Background

    Get PDF
    Recently we found compelling evidence for a gravitational-wave background with Hellings and Downs (HD) correlations in our 15 yr data set. These correlations describe gravitational waves as predicted by general relativity, which has two transverse polarization modes. However, more general metric theories of gravity can have additional polarization modes, which produce different interpulsar correlations. In this work, we search the NANOGrav 15 yr data set for evidence of a gravitational-wave background with quadrupolar HD and scalar-transverse (ST) correlations. We find that HD correlations are the best fit to the data and no significant evidence in favor of ST correlations. While Bayes factors show strong evidence for a correlated signal, the data does not strongly prefer either correlation signature, with Bayes factors ∼2 when comparing HD to ST correlations, and ∼1 for HD plus ST correlations to HD correlations alone. However, when modeled alongside HD correlations, the amplitude and spectral index posteriors for ST correlations are uninformative, with the HD process accounting for the vast majority of the total signal. Using the optimal statistic, a frequentist technique that focuses on the pulsar-pair cross-correlations, we find median signal-to-noise ratios of 5.0 for HD and 4.6 for ST correlations when fit for separately, and median signal-to-noise ratios of 3.5 for HD and 3.0 for ST correlations when fit for simultaneously. While the signal-to-noise ratios for each of the correlations are comparable, the estimated amplitude and spectral index for HD are a significantly better fit to the total signal, in agreement with our Bayesian analysis

    The NANOGrav 15-year data set: Search for Transverse Polarization Modes in the Gravitational-Wave Background

    Full text link
    Recently we found compelling evidence for a gravitational wave background with Hellings and Downs (HD) correlations in our 15-year data set. These correlations describe gravitational waves as predicted by general relativity, which has two transverse polarization modes. However, more general metric theories of gravity can have additional polarization modes which produce different interpulsar correlations. In this work we search the NANOGrav 15-year data set for evidence of a gravitational wave background with quadrupolar Hellings and Downs (HD) and Scalar Transverse (ST) correlations. We find that HD correlations are the best fit to the data, and no significant evidence in favor of ST correlations. While Bayes factors show strong evidence for a correlated signal, the data does not strongly prefer either correlation signature, with Bayes factors 2\sim 2 when comparing HD to ST correlations, and 1\sim 1 for HD plus ST correlations to HD correlations alone. However, when modeled alongside HD correlations, the amplitude and spectral index posteriors for ST correlations are uninformative, with the HD process accounting for the vast majority of the total signal. Using the optimal statistic, a frequentist technique that focuses on the pulsar-pair cross-correlations, we find median signal-to-noise-ratios of 5.0 for HD and 4.6 for ST correlations when fit for separately, and median signal-to-noise-ratios of 3.5 for HD and 3.0 for ST correlations when fit for simultaneously. While the signal-to-noise-ratios for each of the correlations are comparable, the estimated amplitude and spectral index for HD are a significantly better fit to the total signal, in agreement with our Bayesian analysis.Comment: 11 pages, 5 figure
    corecore