93 research outputs found
A search for very young Planetary Nebulae
Despite numerous efforts, the transition from Asymptotic Giant Branch (AGB)
stars to Planetary Nebulae (PN) is a poorly understood phase of stellar
evolution. We have therefore carried out interferometric (VLA) radio
observations of a sample of hot post-AGB stars, selected on the basis of their
optical and infrared properties. Ten sources out of the 16 observed were
detected. This indicates that most of our targets are surrounded by a nebula
where the ionization has already started. This definitively determines the
evolutionary status of the selected sources and provides us with a unique
sample of very young Planetary Nebulae (yPNe). A comparison with another sample
of yPNe confirms our working hypothesis that our targets are indeed very young,
probably just in the transition toward PN. Finding transition objects is
extremely important as they can provide unique clues for a better understanding
of this important phase of stellar evolution.Comment: 10 pages, 6 figure
Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF
The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at
the Fermilab Long-Baseline Neutrino Facility (LBNF) is described
Brain metastasis development and poor survival associated with carcinoembryonic antigen (CEA) level in advanced non-small cell lung cancer: a prospective analysis
<p>Abstract</p> <p>Background</p> <p>Central nervous system is a common site of metastasis in NSCLC and confers worse prognosis and quality of life. The aim of this prospective study was to evaluate the prognostic significance of clinical-pathological factors (CPF), serum CEA levels, and EGFR and HER2 tissue-expression in brain metastasis (BM) and overall survival (OS) in patients with advanced NSCLC.</p> <p>Methods</p> <p>In a prospective manner, we studied 293 patients with NSCLC in IIIB-IV clinical stage. They received standard chemotherapy. CEA was measured prior to treatment; EGFR and HER2 were evaluated by immunohistochemistry. BM development was confirmed by MRI in symptomatic patients.</p> <p>Results</p> <p>BM developed in 27, and 32% of patients at 1 and 2 years of diagnosis with adenocarcinoma (RR 5.2; 95% CI, 1.002–29; p = 0.05) and CEA ≥ 40 ng/mL (RR 11.4; 95% CI, 1.7–74; <it>p </it>< 0.01) as independent associated factors. EGFR and HER2 were not statistically significant. Masculine gender (RR 1.4; 95% CI, 1.002–1.9; <it>p </it>= 0.048), poor performance status (RR 1.8; 95% CI, 1.5–2.3; <it>p </it>= 0.002), advanced clinical stage (RR 1.44; 95% CI, 1.02–2; <it>p </it>= 0.04), CEA ≥ 40 ng/mL (RR 1.5; 95% CI, 1.09–2.2; <it>p </it>= 0.014) and EGFR expression (RR 1.6; 95% CI, 1.4–1.9; <it>p </it>= 0.012) were independent associated factors to worse OS.</p> <p>Conclusion</p> <p>High CEA serum level is a risk factor for BM development and is associated with poor prognosis in patients with advanced NSCLC. Surface expression of CEA in tumor cells could be the physiopathological mechanism for invasion to CNS.</p
The DUNE Far Detector Interim Design Report, Volume 3: Dual-Phase Module
The DUNE IDR describes the proposed physics program and technical designs of the DUNE far detector modules in preparation for the full TDR to be published in 2019. It is intended as an intermediate milestone on the path to a full TDR, justifying the technical choices that flow down from the high-level physics goals through requirements at all levels of the Project. These design choices will enable the DUNE experiment to make the ground-breaking discoveries that will help to answer fundamental physics questions. Volume 3 describes the dual-phase module's subsystems, the technical coordination required for its design, construction, installation, and integration, and its organizational structure
Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites
The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions.
The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness
of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence
were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density
and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that
the wood in the starch composites did not prevent water loss from the samples.Peer reviewe
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Approaches in biotechnological applications of natural polymers
Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
Mitochondrial genetic diversity, selection and recombination in a canine transmissible cancer.
Canine transmissible venereal tumour (CTVT) is a clonally transmissible cancer that originated approximately 11,000 years ago and affects dogs worldwide. Despite the clonal origin of the CTVT nuclear genome, CTVT mitochondrial genomes (mtDNAs) have been acquired by periodic capture from transient hosts. We sequenced 449 complete mtDNAs from a global population of CTVTs, and show that mtDNA horizontal transfer has occurred at least five times, delineating five tumour clades whose distributions track two millennia of dog global migration. Negative selection has operated to prevent accumulation of deleterious mutations in captured mtDNA, and recombination has caused occasional mtDNA re-assortment. These findings implicate functional mtDNA as a driver of CTVT global metastatic spread, further highlighting the important role of mtDNA in cancer evolution.Wellcome Trust Investigator Award, 102942/Z/13/A
Elizabeth P Murchison
Leverhulme Trust Philip Leverhulme Prize Elizabeth P Murchison
Royal Society Research Grant, RG130615 Elizabeth P Murchiso
Somatic evolution and global expansion of an ancient transmissible cancer lineage
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Previous issue date: 2019-08-02GPD Charitable TrustLeverhulme TrustThe canine transmissible venereal tumor (CTVT) is a cancer lineage that arose several millennia ago and survives by “metastasizing” between hosts through cell transfer. The somatic mutations in this cancer record its phylogeography and evolutionary history. We constructed a time-resolved phylogeny from 546 CTVT exomes and describe the lineage's worldwide expansion. Examining variation in mutational exposure, we identify a highly context-specific mutational process that operated early in the cancer's evolution but subsequently vanished, correlate ultraviolet-light mutagenesis with tumor latitude, and describe tumors with heritable hyperactivity of an endogenous mutational process. CTVT displays little evidence of ongoing positive selection, and negative selection is detectable only in essential genes. We illustrate how long-lived clonal organisms capture changing mutagenic environments, and reveal that neutral genetic drift is the dominant feature of long-term cancer evolution.Transmissible Cancer Group Department of Veterinary Medicine University of CambridgeAnimal Management in Rural and Remote Indigenous Communities (AMRRIC)World VetsAnimal Shelter Stichting Dierenbescherming SurinameSikkim Anti-Rabies and Animal Health Programme Department of Animal Husbandry Livestock Fisheries and Veterinary Services Government of SikkimRoyal (Dick) School of Veterinary Studies Roslin Institute University of Edinburgh Easter Bush CampusConserLab Animal Preventive Medicine Department Faculty of Animal and Veterinary Sciences University of ChileCorozal Veterinary Hospital University of PanamáSt. George's UniversityNakuru District Veterinary Scheme LtdAnimal Medical CentreInternational Animal Welfare Training Institute UC Davis School of Veterinary MedicineCentro Universitário de Rio Preto (UNIRP)Department of Clinical and Veterinary Surgery São Paulo State University (UNESP)Ladybrand Animal ClinicVeterinary Clinic Sr. Dog'sWorld Vets Latin America Veterinary Training CenterNational Veterinary Research InstituteAnimal ClinicIntermunicipal Stray Animals Care Centre (DIKEPAZ)Animal Protection Society of SamoaFaculty of Veterinary Science University of ZuliaVeterinary Clinic BIOCONTROLFaculty of Veterinary Medicine School of Health Sciences University of ThessalyVeterinary Clinic El Roble Animal Healthcare Network Faculty of Animal and Veterinary Sciences University of ChileOnevetGroup Hospital Veterinário BernaUniversidade Vila VelhaVeterinary Clinic ZoovetservisÉcole Inter-états des Sciences et Médecine Vétérinaires de DakarDepartment of Small Animal Medicine Faculty of Veterinary Medicine Utrecht UniversityVetexpert Veterinary GroupVeterinary Clinic Lopez QuintanaClinique Veterinaire de Grand Fond Saint Gilles les BainsDepartment of Veterinary Sciences University of MessinaFacultad de Medicina Veterinaria y Zootecnia Universidad Autónoma del Estado de MéxicoSchool of Veterinary Medicine Universidad de las AméricasCancer Development and Innate Immune Evasion Lab Champalimaud Center for the UnknownTouray and Meyer Vet ClinicHillside Animal HospitalKampala Veterinary SurgeryAsavet Veterinary CharitiesVets Beyond BordersFaculty of Veterinary Medicine Autonomous University of YucatanLaboratorio de Patología Veterinaria Universidad de CaldasInterdisciplinary Centre of Research in Animal Health (CIISA) Faculty of Veterinary Medicine University of LisbonFour Paws InternationalHelp in SufferingVeterinary Clinic Dr José RojasDepartment of Biotechnology Balochistan University of Information Technology Engineering and Management SciencesCorozal Veterinary ClinicVeterinary Clinic VetmasterState Hospital of Veterinary MedicineJomo Kenyatta University of Agriculture and TechnologyLaboratory of Biomedicine and Regenerative Medicine Department of Clinical Sciences Faculty of Animal and Veterinary Sciences University of ChileFaculty of Veterinary and Agricultural Sciences University of MelbourneAnimal Anti Cruelty LeagueClinical Sciences Department Faculty of Veterinary Medicine BucharestDepartment of Pathology Faculty of Veterinary Medicine Ankara UniversityFaculty of Veterinary Sciences National University of AsuncionLilongwe Society for Protection and Care of Animals (LSPCA)Wellcome Sanger InstituteDepartment of Cellular and Molecular Medicine University of California San DiegoDepartment of Clinical and Veterinary Surgery São Paulo State University (UNESP)Leverhulme Trust: 102942/Z/13/
Recurrent horizontal transfer identifies mitochondrial positive selection in a transmissible cancer
Abstract: Autonomous replication and segregation of mitochondrial DNA (mtDNA) creates the potential for evolutionary conflict driven by emergence of haplotypes under positive selection for ‘selfish’ traits, such as replicative advantage. However, few cases of this phenomenon arising within natural populations have been described. Here, we survey the frequency of mtDNA horizontal transfer within the canine transmissible venereal tumour (CTVT), a contagious cancer clone that occasionally acquires mtDNA from its hosts. Remarkably, one canine mtDNA haplotype, A1d1a, has repeatedly and recently colonised CTVT cells, recurrently replacing incumbent CTVT haplotypes. An A1d1a control region polymorphism predicted to influence transcription is fixed in the products of an A1d1a recombination event and occurs somatically on other CTVT mtDNA backgrounds. We present a model whereby ‘selfish’ positive selection acting on a regulatory variant drives repeated fixation of A1d1a within CTVT cells
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