150 research outputs found

    First ancient mitochondrial human genome from a prepastoralist Southern African

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    The oldest contemporary human mitochondrial lineages arose in Africa. The earliest divergent extant maternal offshoot, namely haplogroup L0d, is represented by click-­‐speaking forager peoples of Southern Africa. Broadly defined as Khoesan, contemporary Khoesan are today largely restricted to the semi-­‐ desert regions of Namibia and Botswana, while archeological, historical and genetic evidence promotes a once broader southerly dispersal of click-­‐speaking peoples including southward migrating pastoralists and indigenous marine-­‐foragers. Today extinct, no genetic data has been recovered from the indigenous peoples that once sustained life along the southern coastal waters of Africa pre-­‐pastoral arrival. In this study we generate a complete mitochondrial genome from a 2,330 year old male skeleton, confirmed via osteological and archeological analysis as practicing a marine-­‐based forager existence. The ancient mtDNA represents a new L0d2c lineage (L0d2c1c) that is today, unlike its Khoe-­‐language based sister-­‐ clades (L0d2c1a and L0d2c1b) most closely related to contemporary indigenous San-­‐speakers (specifically Ju). Providing the first genomic evidence that pre-­‐pastoral Southern African marine foragers carried the earliest diverged maternal modern human lineages, this study emphasizes the significance of Southern African archeological remains in defining early modern human origins.J. Craig Venter Family Foundation, La Jolla, CA, U.S.A. and the Max Planck Society (within the laboratory of Svante Pääbo).http://gbe.oxfordjournals.orghb201

    Progress on a gas-accepting ion source for continuous-flow accelerator mass spectrometry

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    Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 259 (2007): 83-87, doi:10.1016/j.nimb.2007.01.189.A gas-accepting microwave-plasma ion source is being developed for continuous-flow Accelerator Mass Spectrometry (AMS). Characteristics of the ion source will be presented. Schemes for connecting a gas or liquid chromatograph to the ion source will also be discussed

    Next generation mapping reveals novel large genomic rearrangements in prostate cancer

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    Complex genomic rearrangements are common molecular events driving prostate carcinogenesis. Clinical significance, however, has yet to be fully elucidated. Detecting the full range and subtypes of large structural variants (SVs), greater than one kilobase in length, is challenging using clinically feasible next generation sequencing (NGS) technologies. Next generation mapping (NGM) is a new technology that allows for the interrogation of megabase length DNA molecules outside the detection range of single-base resolution NGS. In this study, we sought to determine the feasibility of using the Irys (Bionano Genomics Inc.) nanochannel NGM technology to generate whole genome maps of a primary prostate tumor and matched blood from a Gleason score 7 (4 + 3), ETS-fusion negative prostate cancer patient. With an effective mapped coverage of 35X and sequence coverage of 60X, and an estimated 43% tumor purity, we identified 85 large somatic structural rearrangements and 6,172 smaller somatic variants, respectively. The vast majority of the large SVs (89%), of which 73% are insertions, were not detectable ab initio using high-coverage short-read NGS. However, guided manual inspection of single NGS reads and de novo assembled scaffolds of NGM-derived candidate regions allowed for confirmation of 94% of these large SVs, with over a third impacting genes with oncogenic potential. From this single-patient study, the first cancer study to integrate NGS and NGM data, we hypothesise that there exists a novel spectrum of large genomic rearrangements in prostate cancer, that these large genomic rearrangements are likely early events in tumorigenesis, and they have potential to enhance taxonomy.This work was supported by Movember Australia and the Prostate Cancer Foundation Australia (PCFA) as part of the Movember Revolutionary Team Award (MRTA) to the Garvan Institute of Medical Research program on prostate cancer bone metastasis (ProMis to P.I.C. and V.M.H.) dedicated to establishing NGM for clinically relevant prostate cancer, and the Australian Prostate Cancer Research Centre NSW (APCRC-NSW). Participant recruitment and sampling was supported by the Cancer Association of South Africa (CANSA to M.S.R.B and V.M.H.). W.J. is supported by APCRC-NSW, E.K.F.C. and D.C.P. are partly supported by ProMis, P.I.C. is supported by Mrs Janice Gibson and the Ernest Heine Family Foundation, Australia, and V.M.H. is supported by the University of Sydney Foundation and Petre Foundation, Australia.www.impactjournals.com/oncotargetam2018School of Health Systems and Public Health (SHSPH

    D* Production in Deep Inelastic Scattering at HERA

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    This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel D+(D0Kπ+)π+D^{*+}\to (D^0 \to K^- \pi^+) \pi^+ (+ c.c.) has been used in the study. The e+pe^+p cross section for inclusive D^{*\pm} production with 5<Q2<100GeV25<Q^2<100 GeV^2 and y<0.7y<0.7 is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {1.3<pT(D±)<9.01.3<p_T(D^{*\pm})<9.0 GeV and η(D±)<1.5| \eta(D^{*\pm}) |<1.5}. Differential cross sections as functions of p_T(D^{*\pm}), η(D±),W\eta(D^{*\pm}), W and Q2Q^2 are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and η\eta(D^{*\pm}), the charm contribution F2ccˉ(x,Q2)F_2^{c\bar{c}}(x,Q^2) to the proton structure function is determined for Bjorken xx between 2 \cdot 104^{-4} and 5 \cdot 103^{-3}.Comment: 17 pages including 4 figure

    Observation of Scaling Violations in Scaled Momentum Distributions at HERA

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    Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of xx and Q2Q^2 using the ZEUS detector. The evolution of the scaled momentum, xpx_p, with Q2,Q^2, in the range 10 to 1280 GeV2GeV^2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2Q^2.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

    Genome-wide interrogation of structural variation reveals novel African-specific prostate cancer oncogenic drivers

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    ADDITIONAL FILE 1: FIGURE S1. Concordant SV call generation from Manta and GRIDSS. FIGURE S2. Summary of SVs in each type, compared to other studies. FIGURE S3. CIRCOS plot of hyper-SV mutated tumours. FIGURE S4. The spread of SV breakpoints and samples in each 1 Mbp genomic bin. FIGURE S5. TMPRSS2-ERG fusion with interstitial region retention. TABLE S1. Clinical and pathological characteristics of 180 prostate cancer patients included in this study. TABLE S2. Biallelic assessment of CDK12 in hyper-duplicated samples. TABLE S3. Biallelic assessment of BRCA2 in hyper-deleted samples.ADDITIONAL FILE 2: TABLE S4. Summary of gene fusions identified from SVs. ADDITIONAL FILE 3: TABLE S5. SV calls resulting in gene fusions.DATA AND MATERIALS AVAILABILITY : The datasets analysed in this study were obtained and accessible through Jaratlerdsiri et al [6], with sequence data deposited in the European GenomePhenome Archive (EGA; https://ega-archive.org) under overarching accession EGAS00001006425 and including the Southern African Prostate Cancer Study (SAPCS) Dataset (EGAD00001009067) and Garvan/St Vincent’s Prostate Cancer Database (EGAD00001009066). The computational code used to analyse SV subtypes, SV hotspots and gene fusions is available on GitHub [68].BACKGROUND : African ancestry is a significant risk factor for advanced prostate cancer (PCa). Mortality rates in sub- Saharan Africa are 2.5-fold greater than global averages. However, the region has largely been excluded from the benefits of whole genome interrogation studies. Additionally, while structural variation (SV) is highly prevalent, PCa genomic studies are still biased towards small variant interrogation. METHODS : Using whole genome sequencing and best practice workflows, we performed a comprehensive analysis of SVs for 180 (predominantly Gleason score ≥ 8) prostate tumours derived from 115 African, 61 European and four ancestrally admixed patients. We investigated the landscape and relationship of somatic SVs in driving ethnic disparity (African versus European), with a focus on African men from southern Africa. RESULTS : Duplication events showed the greatest ethnic disparity, with a 1.6- (relative frequency) to 2.5-fold (count) increase in African-derived tumours. Furthermore, we found duplication events to be associated with CDK12 inactivation and MYC copy number gain, and deletion events associated with SPOP mutation. Overall, African-derived tumours were 2-fold more likely to present with a hyper-SV subtype. In addition to hyper-duplication and deletion subtypes, we describe a new hyper-translocation subtype. While we confirm a lower TMPRSS2-ERG fusion-positive rate in tumours from African cases (10% versus 33%), novel African-specific PCa ETS family member and TMPRSS2 fusion partners were identified, including LINC01525, FBXO7, GTF3C2, NTNG1 and YPEL5. Notably, we found 74 somatic SV hotspots impacting 18 new candidate driver genes, with CADM2, LSAMP, PTPRD, PDE4D and PACRG having therapeutic implications for African patients. CONCLUSIONS : In this first African-inclusive SV study for high-risk PCa, we demonstrate the power of SV interrogation for the identification of novel subtypes, oncogenic drivers and therapeutic targets. Identifying a novel spectrum of SVs in tumours derived from African patients provides a mechanism that may contribute, at least in part, to the observed ethnic disparity in advanced PCa presentation in men of African ancestry.The Medical Health and Medical Research Council (NHMRC) of Australia, University of Sydney Bridging Grant, the USA. Department of Defense (DoD) Prostate Cancer Research Program (PCRP) Idea Development.https://genomemedicine.biomedcentral.comam2023School of Health Systems and Public Health (SHSPH

    A philosophical analysis of the evidence-based medicine debate

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    BACKGROUND: The term "evidence-based medicine" (or EBM) was introduced about ten years ago, and there has been considerable debate about the value of EBM. However, this debate has sometimes been obscured by a lack of conceptual clarity concerning the nature and status of EBM. DISCUSSION: First, we note that EBM proponents have obscured the current debate by defining EBM in an overly broad, indeed almost vacuous, manner; we offer a clearer account of EBM and its relation to the alternative approaches to medicine. Second, while EBM proponents commonly cite the philosophical work of Thomas Kuhn and claim that EBM is a Kuhnian 'paradigm shift,' we argue that such claims are seriously mistaken and unduly polarize the EBM debate. Third, we suggest that it is much more fruitful to understand the relationship between EBM and its alternatives in light of a different philosophical metaphor: W.V. Quine's metaphor of the web of belief. Seen in this way, we argue that EBM is an approach to medical practice that is indeed importantly different from the alternatives. SUMMARY: We can have a more productive debate about the value of EBM by being clearer about the nature of EBM and its relationship to alternative approaches to medicine

    African-specific molecular taxonomy of prostate cancer

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    Data availability DNA-sequencing data have been deposited at the European Genome- Phenome Archive (EGA) under overarching accession EGAS00001006425 and including the Southern African Prostate Cancer Study (SAPCS) Dataset (EGAD00001009067 and Garvan/St Vincent’s Prostate Cancer Database EGAD00001009066). Academic researchers meeting the data-access policy criteria may apply for data access through the respective data access committees. CPGEA data are available through http://www.cpgea.com. PCAWG data are available at ICGC Data Portal (https://dcc.icgc.org/releases/PCAWG).Prostate cancer is characterized by considerable geo-ethnic disparity. African ancestry is a significant risk factor, with mortality rates across sub-Saharan Africa of 2.7-fold higher than global averages. The contributing genetic and non-genetic factors, and associated mutational processes, are unknown. Here, through whole-genome sequencing of treatment-naive prostate cancer samples from 183 ancestrally (African versus European) and globally distinct patients, we generate a large cancer genomics resource for sub-Saharan Africa, identifying around 2 million somatic variants. Significant African-ancestry-specific findings include an elevated tumour mutational burden, increased percentage of genome alteration, a greater number of predicted damaging mutations and a higher total of mutational signatures, and the driver genes NCOA2, STK19, DDX11L1, PCAT1 and SETBP1. Examining all somatic mutational types, we describe a molecular taxonomy for prostate cancer differentiated by ancestry and defined as global mutational subtypes (GMS). By further including Chinese Asian data, we confirm that GMS-B (copy-number gain) and GMS-D (mutationally noisy) are specific to African populations, GMS-A (mutationally quiet) is universal (all ethnicities) and the African–European-restricted subtype GMS-C (copy-number losses) predicts poor clinical outcomes. In addition to the clinical benefit of including individuals of African ancestry, our GMS subtypes reveal different evolutionary trajectories and mutational processes suggesting that both common genetic and environmental factors contribute to the disparity between ethnicities. Analogous to gene–environment interaction—defined here as a different effect of an environmental surrounding in people with different ancestries or vice versa—we anticipate that GMS subtypes act as a proxy for intrinsic and extrinsic mutational processes in cancers, promoting global inclusion in landmark studies.The National Health and Medical Research Council (NHMRC) of Australia, NHMRC Ideas Grants, University of Sydney Bridging Grant, the US Department of Defense (DoD) Prostate Cancer Research Program (PCRP) Idea Development Award TARGET Africa.http://www.nature.com/natuream2023School of Health Systems and Public Health (SHSPH

    Observation of Events with an Energetic Forward Neutron in Deep Inelastic Scattering at HERA

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    In deep inelastic neutral current scattering of positrons and protons at the center of mass energy of 300 GeV, we observe, with the ZEUS detector, events with a high energy neutron produced at very small scattering angles with respect to the proton direction. The events constitute a fixed fraction of the deep inelastic, neutral current event sample independent of Bjorken x and Q2 in the range 3 · 10-4 \u3c xBJ \u3c 6 · 10-3 and 10 \u3c Q2 \u3c 100 GeV2
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