We propose a method for improving the quality of cone-beam tomographic reconstruction done with a C-arm. C-arm scans frequently suffer from incomplete information due to image truncation, limited ...scan length, or other limitations. Our proposed "hybrid reconstruction" method injects information from a prior anatomical model, derived from a subject-specific computed tomography (CT) or from a statistical database (atlas), where the C-arm X-ray data is missing. This significantly reduces reconstruction artifacts with little loss of true information from the X-ray projections. The methods consist of constructing anatomical models, fast rendering of digitally reconstructed radiograph (DRR) projections of the models, rigid or deformable registration of the model and the X-ray images, and fusion of the DRR and X-ray projections, all prior to a conventional filtered back-projection algorithm. Our experiments, conducted with a mobile image intensifier C-arm, demonstrate visually and quantitatively the contribution of data fusion to image quality, which we assess through comparison to a "ground truth" CT. Importantly, we show that a significantly improved reconstruction can be obtained from a C-arm scan as short as 90 ° by complementing the observed projections with DRRs of two prior models, namely an atlas and a preoperative same-patient CT. The hybrid reconstruction principles are applicable to other types of C-arms as well.
Primate Craniofacial Function and Biologyis an integrative volume with broad coverage of current research on primate craniofacial biology and function. Topic headings include: the mammalian ...perspective on primate craniofacial form and function, allometric and comparative morphological studies of primate heads, in vivo research on primate mastication, modeling of the primate masticatory apparatus, primate dental form and function, and palaeoanthropologic studies of primate skulls. Additionally, the volume includes introductory chapters discussing how primatologists study adaptations in primates and a discussion of in vivo approaches for studying primate performance. At present, there are no texts with a similar focus on primate craniofacial biology and no sources that approach this topic from such a wide range of research perspectives. This breadth of research covered by leaders in their respective fields make this volume a unique and innovative contribution to biological anthropology.
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FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
Leukemia initiating cells (LIC) contribute to therapeutic resistance through mutations in cellular self-renewal and survival pathways. NOTCH1 mutations are common in T-cell acute ...lymphoblastic leukemia (T-ALL). However, the role of NOTCH1 activation in human LIC propagation has not been established. Pediatric T-ALL serially transplantable LIC were found to be enriched in the CD34+CD4− and CD34+CD7− fractions of newly diagnosed patient samples. More recently, a CD7+CD1a− glucocorticoid resistant LIC population, capable of engrafting leukemia in NOD/SCID IL2R gamma null (NSG) mice, was identified in primary adult T-ALL. To identify the molecularly characterized potential LIC populations in pediatric T-ALL without proceeding in vitro culture and examine the role of NOTCH1 activation in LIC propagation. 12 pediatric T-ALL samples were sequenced for NOTCH1 mutation examination. Humanized LIC mouse models were established and dosed with either NOTCH1 mAb or IgG1 mAb control at 10 mg/kg intraperitoneally every 4 days for 6 doses. Mice were sacrificed one day after the last dose, and hematopoietic organs were collected for FACS analysis. To further define the LIC populations in pediatric T-ALL, CD34+CD38+CD2+CD7+Lin− and CD34+CD38+CD2+CD7−Lin− cells were isolated from T-ALL primary patients’ blood by FACS sorting and transplanted into neonatal RAG2−/−γc−/− mice to determine their leukemic engraftment potential. Serial transplantations were done for testing the LIC self-renewal capacity. Mouse hematopoietic organs were collected for FACS analysis, mouse brains were sectioned for human cells examination by immunohistochemistry. NOTCH1 and its downstream gene expressions were examined by q-RT-PCR between the T-ALL CD34+ and CD34− populations. Six of 12 pediatric T-ALL patient samples were found NOTCH1 mutation. Mice transplanted with CD34+ and CD34+CD2+CD7+ or CD34+CD2+CD7− cells developed a T-ALL-like disease characterized by pale BM and enlarged spleen, thymus and liver. Human CD34+ enriched cells from NOTCH1 mutated T-ALL maintained leukemic engraftment while an equivalent number of CD34+ cells from NOTCH1 wild type T-ALL did not. T-ALL CD34+ progenitors from NOTCH1 mutated T-ALL have a significant higher engraftment in BM when compared with those from NOTCH1 wild type T-ALL. CD34+CD2+CD7+ and CD34+CD2+CD7− populations are more prominent in NOTCH1 mutated samples. Both the human CD34+ and CD34+CD2+CD7+ populations were significantly reduced in BM when treated with hN1 mAb in vivo. NOTCH1 and its downstream genes expression were significantly reduced in NOTCH1 mutated CD34+ cells when compared with CD34− cells. Human T-ALL LIC have enhanced NOTCH1 expression; CD34+CD2+CD7+ and CD34+CD2+CD7− subpopulations are enriched for LIC activity in pediatric T-ALL; A selective hN1 mAb inhibits human T-ALL LIC survival and self-renewal in vivo.
Citation Format: {Authors}. {Abstract title} abstract. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1011. doi:1538-7445.AM2012-1011
Investigators seeking to identify genetic prognostic markers in a clinical trial to treat acute myeloid leukemia found that minimal residual disease, detected by the presence of mutation in
NPM1,
...provided prognostic information independent of other risk factors.
Although acute myeloid leukemia (AML) is genetically less complex than many other tumors, the condition is molecularly heterogeneous.
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Despite improved understanding of the mutational landscape, treatment decisions, particularly regarding allogeneic stem-cell transplantation, remain guided by cytogenetic analysis, a limited panel of molecular genetic markers, and morphology-based assessment of remission.
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Currently, a predicted risk of relapse of more than 35% is widely considered to warrant stem-cell transplantation during the first remission.
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Patients with high-risk disease undergo stem-cell transplantation if feasible, whereas those with low-risk disease usually do not. However, there is uncertainty about the role of transplantation in patients . . .
Characterization of species diversity of zooplankton is key to understanding, assessing, and predicting the function and future of pelagic ecosystems throughout the global ocean. The marine ...zooplankton assemblage, including only metazoans, is highly diverse and taxonomically complex, with an estimated ~28,000 species of 41 major taxonomic groups. This review provides a comprehensive summary of DNA sequences for the barcode region of mitochondrial cytochrome oxidase I (COI) for identified specimens. The foundation of this summary is the MetaZooGene Barcode Atlas and Database (MZGdb), a new open-access data and metadata portal that is linked to NCBI GenBank and BOLD data repositories. The MZGdb provides enhanced quality control and tools for assembling COI reference sequence databases that are specific to selected taxonomic groups and/or ocean regions, with associated metadata (e.g., collection georeferencing, verification of species identification, molecular protocols), and tools for statistical analysis, mapping, and visualization. To date, over 150,000 COI sequences for ~ 5600 described species of marine metazoan plankton (including holo- and meroplankton) are available via the MZGdb portal. This review uses the MZGdb as a resource for summaries of COI barcode data and metadata for important taxonomic groups of marine zooplankton and selected regions, including the North Atlantic, Arctic, North Pacific, and Southern Oceans. The MZGdb is designed to provide a foundation for analysis of species diversity of marine zooplankton based on DNA barcoding and metabarcoding for assessment of marine ecosystems and rapid detection of the impacts of climate change.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
ABSTRACT
Soil is one of the most biodiverse terrestrial habitats. Yet, we lack an integrative conceptual framework for understanding the patterns and mechanisms driving soil biodiversity. One of the ...underlying reasons for our poor understanding of soil biodiversity patterns relates to whether key biodiversity theories (historically developed for aboveground and aquatic organisms) are applicable to patterns of soil biodiversity. Here, we present a systematic literature review to investigate whether and how key biodiversity theories (species–energy relationship, theory of island biogeography, metacommunity theory, niche theory and neutral theory) can explain observed patterns of soil biodiversity. We then discuss two spatial compartments nested within soil at which biodiversity theories can be applied to acknowledge the scale‐dependent nature of soil biodiversity.
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Diversity and distribution of Victoria Land biota Adams, Byron J.; Bardgett, Richard D.; Ayres, Edward ...
Soil biology & biochemistry,
10/2006, Volume:
38, Issue:
10
Journal Article, Conference Proceeding
Peer reviewed
Understanding the relationship between soil biodiversity and ecosystem functioning is critical to predicting and monitoring the effects of ecosystem changes on important soil processes. However, most ...of Earth's soils are too biologically diverse to identify each species present and determine their functional role in food webs. The soil ecosystems of Victoria Land (VL) Antarctica are functionally and biotically simple, and serve as in situ models for determining the relationship between biodiversity and ecosystem processes. For a few VL taxa (microarthropods, nematodes, algae, mosses and lichens), species diversity has been intensively assessed in highly localized habitats, but little is known of how community assemblages vary across broader spatial scales, or across latitudinal and environmental gradients. The composition of tardigrade, rotifer, protist, fungal and prokaryote communities is emerging. The latter groups are the least studied, but potentially the most diverse. Endemism is highest for microarthropods and nematodes, less so for tardigrades and rotifers, and apparently low for mosses, lichens, protists, fungi and prokaryotes. Much of what is known about VL diversity and distribution occurs in an evolutionary and ecological vacuum; links between taxa and functional role in ecosystems are poorly known and future studies must utilize phylogenetic information to infer patterns of community assembly, speciation, extinction, population processes and biogeography. However, a comprehensive compilation of all the species that participate in soil ecosystem processes, and their distribution across regional and landscape scales is immediately achievable in VL with the resources, tools, and expertise currently available. We suggest that the soil ecosystems of VL should play a major role in exploring the relationship between biodiversity and ecosystem functioning, and in monitoring the effects of environmental change on soil processes in real time and space.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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