287 research outputs found

    Should Networks Supplant Tree Building?

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    Recent studies suggested that network methods should supplant tree building as the basis of genealogical analysis. This proposition is based upon two arguments. First is the observation that bacterial and archaeal lineages experience processes oppositional to bifurcation and hence the representation of the evolutionary process in a tree like structure is illogical. Second is the argument tree building approaches are circular—you ask for a tree and you get one, which pins a verificationist label on tree building that, if correct, should be the end of phylogenetic analysis as we currently know it. In this review, we examine these questions and suggest that rumors of the death of the bacterial tree of life are exaggerated at best

    Development of a qPCR assay for the quantification of canine autosomal DNA recovered from livestock attacks

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    The absence of a standardised method to quantify canine DNA recovered from livestock attacks leaves forensic providers without an important quality control step to help support their decision making. Typically used to normalise the amount of DNA for STR amplification, modern forensic DNA quantification approaches use qPCR of target genes and can also include an Internal Positive Controls (IPC) to determine the presence of PCR inhibitors. The co-amplification of livestock DNA alongside canine DNA has meant that previously developed qPCR methods are not suitable for use so a standardised approach is needed. This research describes the development of a Taq-man multiplex qPCR assay that simultaneously quantifies the autosomal MC1R and Y-specific SRY gene to determine the concentration of canine DNA recovered from attacked livestock. Data suggests that the method is robust and reproducible with no significant difference in the standard curves produced from multiple runs orfrom different DNA standards derived from different canines. Assay sensitivity of between 15 and 31 pg is consistent with other forensic quantification assays and also in line with the sensitivity of the two tested canine STR kits, Canine Genotype 2.1 Kit and CaDNAP Panels 1 and 2. The assay is highly specific to canines when tested against 163 different dogs representing 33 different breeds and no cross-amplification of non-target species’ DNA was observed even from livestock DNA tested at 31.25 ng/µl. This strongly suggests that any DNA detected on evidence collected from attacked livestock is canine. The assay also shows robust tolerance tocommon livestock inhibitors continuing to amplify when inhibitor-spiked DNA samples were tested. Both mixed and inhibited DNA samples underwent STR typing using two canine forensic STR kits with data showing the Canine Genotype 2.1 Kit displaying pronounced cross-amplification of livestock DNA and and/or extensive PCR inhibition leading to the complete loss of amplification when using this kit. Conversely the CaDNAP Panels 1 and 2 showed little cross-amplification of livestock DNA and improved inhibitor tolerance suggesting that thisapproach was better suited for the analysis of livestock attack samples. Findings are discussed and the impact of the observations on future work in this area are explored

    VUE: Civic Investment in Public Education Winter 2012, Number 32

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    The Annenberg Institute for School Reform (AISR) at Brown University partnered with Public Education Network to highlight the findings of PEN's National Commission on Civic Investment in Public Education, which met for 18 months and issued its final report in May, 2011. AISR dedicated its Winter 2012 issue of Voices in Urban Education (VUE) to the topic of civic investment in public education. The fifteen members of the National Commission for Civic Investment in Public Education have performed an extraordinary service for this nation and for America's schoolchildren. The Commission's work was ably led by co-chairs Richard W. Riley, former U.S. Secretary of Education (1993 -- 2001) and Linda Darling-Hammond, world-renowned education scholar and professor of education at Stanford University. Other members included leaders from the corporate, philanthropic, and nonprofit sectors; educators; researchers; and public education support organization leaders from around the country. Together they shared a commitment to expand civic knowledge and support of public education through citizen involvement. Contents:The National Commission for Civic Investment in Public Education by Wendy PuriefoyReaffirming the Dream: The Case for Civic Investment by Richard W. Riley and Linda Darling-HammondA Story of Civic Investment in Public Education by Susan V. BerresfordThe Right Funds for Reinvestment by Erwin de LeonA Failure of Philanthropy: American Charity Shortchanges the Poor, and Public Policy is Partly to Blame by Rob Reic

    Beliefs About Medication and Uptake of Preventive Therapy in Women at Increased Risk of Breast Cancer: Results From a Multicenter Prospective Study

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    Introduction Uptake of preventive therapies for breast cancer is low. We examined whether women at increased risk of breast cancer can be categorized into groups with similar medication beliefs, and whether belief group membership was prospectively associated with uptake of preventive therapy. Patients and Methods Women (n = 732) attending an appointment to discuss breast cancer risk were approached; 408 (55.7%) completed the Beliefs About Medicines and the Perceived Sensitivity to Medicines questionnaires. Uptake of tamoxifen at 3 months was reported in 258 (63.2%). The optimal number of belief groups were identified using latent profile analysis. Results Uptake of tamoxifen was 14.7% (38/258). One in 5 women (19.4%; 78/402) reported a strong need for tamoxifen. The model fit statistics supported a 2-group model. Both groups held weak beliefs about their need for tamoxifen for current and future health. Group 2 (38%; 154/406 of the sample) reported stronger concerns about tamoxifen and medicines in general, and stronger perceived sensitivity to the negative effects of medicines compared with group 1 (62%; 252/406). Women with low necessity and lower concerns (group 1) were more likely to initiate tamoxifen (18.3%; 33/180) than those with low necessity and higher concerns (group 2) (6.4%; 5/78). After adjusting for demographic and clinical factors, the odds ratio was 3.37 (95% confidence interval, 1.08-10.51; P = .036). Conclusion Uptake of breast cancer preventive therapy was low. A subgroup of women reported low need for preventive therapy and strong medication concerns. These women were less likely to initiate tamoxifen. Medication beliefs are targets for supporting informed decision-making

    Determination of the Processes Driving the Acquisition of Immunity to Malaria Using a Mathematical Transmission Model

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    Acquisition of partially protective immunity is a dominant feature of the epidemiology of malaria among exposed individuals. The processes that determine the acquisition of immunity to clinical disease and to asymptomatic carriage of malaria parasites are poorly understood, in part because of a lack of validated immunological markers of protection. Using mathematical models, we seek to better understand the processes that determine observed epidemiological patterns. We have developed an age-structured mathematical model of malaria transmission in which acquired immunity can act in three ways (“immunity functions”): reducing the probability of clinical disease, speeding the clearance of parasites, and increasing tolerance to subpatent infections. Each immunity function was allowed to vary in efficacy depending on both age and malaria transmission intensity. The results were compared to age patterns of parasite prevalence and clinical disease in endemic settings in northeastern Tanzania and The Gambia. Two types of immune function were required to reproduce the epidemiological age-prevalence curves seen in the empirical data; a form of clinical immunity that reduces susceptibility to clinical disease and develops with age and exposure (with half-life of the order of five years or more) and a form of anti-parasite immunity which results in more rapid clearance of parasitaemia, is acquired later in life and is longer lasting (half-life of >20 y). The development of anti-parasite immunity better reproduced observed epidemiological patterns if it was dominated by age-dependent physiological processes rather than by the magnitude of exposure (provided some exposure occurs). Tolerance to subpatent infections was not required to explain the empirical data. The model comprising immunity to clinical disease which develops early in life and is exposure-dependent, and anti-parasite immunity which develops later in life and is not dependent on the magnitude of exposure, appears to best reproduce the pattern of parasite prevalence and clinical disease by age in different malaria transmission settings. Understanding the effector mechanisms underlying these two immune functions will assist in the design of transmission-reducing interventions against malaria

    An Evaluation of the Diagnostic Accuracy of the Grade of Preoperative Biopsy Compared to Surgical Excision in Chondrosarcoma of the Long Bones

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    Chondrosarcoma is the second most common primary malignant bone tumour. Distinguishing between grades is not necessarily straightforward and may alter the disease management. We evaluated the correlation between histological grading of the preoperative image-guided needle biopsy and the resection specimen of 78 consecutive cases of chondrosarcoma of the femur, humerus, and tibia. In 11 instances, there was a discrepancy in histological grade between the biopsy and surgical specimen. Therefore, there was an 85.9% (67/78) accuracy rate for pre-operative histological grading of chondrosarcoma, based on needle biopsy. However, the accuracy of the diagnostic biopsy to distinguish low-grade from high-grade chondrosarcoma was 93.6% (73/78). We conclude that accurate image-guided biopsy is a very useful adjunct in determining histological grade of chondrosarcoma and the subsequent treatment plan. At present, a multidisciplinary approach, comprising experienced orthopaedic surgeons, radiologists, and pathologists, offers the most reliable means of accurately diagnosing and grading of chondrosarcoma of long bones

    In vitro and in vivo studies on the metabolism and pharmacokinetics of the selective gut microbial β-glucuronidase targeting compound Inh 1

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    In vitro studies using rat, mouse, and human microsomes and hepatocytes on the bacterial β-glucuronidase inhibitor 1-((6,8-dimethyl-2-oxo-1,2-dihydroquinolin-3-yl)methyl)-3-(4-ethoxyphenyl)-1-(2-hydroxyethyl)thiourea) (Inh 1) revealed extensive metabolism in all species.The intrinsic clearances of Inh 1 in human, mouse, and rat hepatic microsomes were 30.9, 67.8, and 201µL/min/mg, respectively. For intact hepatocytes intrinsic clearances of 21.6, 96.0, and 129µL/min/10 6 cells were seen for human, mouse and rat, respectively.The metabolism of Inh 1 involved an uncommon desulphurisation reaction in addition to oxidation, deethylation, and conjugation reactions at multiple sites. Six metabolites were detected in microsomal incubations in human and rat, and seven for the mouse. With hepatocytes, 18 metabolites were characterised, 9 for human, and 11 for mouse and rat. Following IV administration to mice (3mg/kg), plasma concentrations of Inh 1 exhibited a monophasic decline with a terminal elimination half-life of 0.91 h and low systemic clearance (11.8% of liver blood flow). After PO dosing to mice (3 mg/kg), peak observed Inh 1 concentrations of 495ng/mL were measured 0.5h post dose, declining to under 10ng/mL at 8h post dose. The absolute oral bioavailability of Inh 1 in the mouse was ca. 26%
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