263 research outputs found

    Electron impact excitation of the a 3B1u electronic state in C2H4: an experimentally benchmarked system?

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    We report on differential and integral cross section measurements for the electron impact excitation of the lowest-lying triplet electronic state (ã 3B1u) in ethylene (C2H4). The energy range of the present experiments was 9 eV–50 eV, with the angular range of the differential cross section measurements being 15°–90°. As the ground electronic state of C2H4 is a 1Ag state, this singlet → triplet excitation process is expected to be dominated by exchange scattering. The present angular distributions are found to support that assertion. Comparison, where possible, with previous experimental results from the University of Fribourg group shows very good agreement, to within the uncertainties on the measured cross sections. Agreement with the available theories, however, is generally marginal with the theories typically overestimating the magnitude of the differential cross sections. Notwithstanding that, the shapes of the theoretical angular distributions were in fact found to be in good accord with the corresponding experimental results

    Two Probable Cases of Infection with Treponema pallidum during the Neolithic Period in Northern Vietnam (~2000-1500B.C.)

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    We would like to thank Dr. Ngo Anh Son, Mr. Bui Van Khanh, and Ms. Nellissa Ling for their assistance with the radiographs, and Dr. Anne Marie E. Snoddy for in-put on the application of a standardized approach to treponemal disease. We thank the associate editor of Bioarchaeology International and three anonymous reviewers for their comments and advice in revising the manuscript. Funding: This research was supported by a National Geographic Early Career Grant (EC-54332R-18), Royal Society of New Zealand Skinner Fund Grant and a University of Otago Doctoral Scholarship.Peer reviewedPostprin

    Two probable cases of infection with Treponema pallidum during the Neolithic period in Northern Vietnam (~2000- 1500B.C.)

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    Skeletal evidence of two probable cases of treponematosis, caused by infection with the bacterium Treponema pallidum, from the northern Vietnamese early Neolithic site of Man Bac (1906–1523 cal B.C.) is described. The presence of nodes of subperiosteal new bone directly associated with superfcial focal cavitations in a young adult male and a seven- year- old child are strongly diagnostic for treponemal disease. Climatic and epidemiological contexts suggest yaws (Treponema pallidum pertenue) as the most likely causative treponeme. This evidence is the oldest discovered in the Asia- Pacific region and is the first well- established pre-Columbian example in this region in terms of diagnosis and secure dating. The coastal ecology, sedentary settlement, and high fertility at the site of Man Bac all provided a biosocial context conducive to the spread of treponemal disease among inhabitants of the site. Co- morbidity with scurvy in both individuals demonstrates that malnutrition during the agricultural transition may have exacerbated the expression of treponematosis in this community. Man Bac is a site of great regional importance owing to its role during the Neolithic transition of Mainland Southeast Asia. During this transition, approximately 4,000 years ago, farmers migrating from southern China into Southeast Asia influenced a number of changes in subsistence and demography and potentially introduced new infectious diseases such as treponematosis to indigenous forager communities. The findings presented here may encourage reevaluation of existing Southeast Asian skeletal samples and demonstrate the importance of using weighted diagnostic criteria for future reporting of treponematosis cases

    Scurvy in the Tropics: Evidence for increasing non-adult micronutrient deficiency with the transition to agriculture in northern Vietnam

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    Objective: Scurvy in non-adults was assessed at the Pre-Neolithic site of Con Co Ngua and the Neolithic site of Man Bac in northern Vietnam to investigate nutritional stress during the agricultural transition in Mainland Southeast Asia (MSEA). Materials: One hundred and four human skeletons under the age of 20 years old were assessed. Methods: Lesions were recorded macroscopically and radiographically. Differential diagnosis using prior established paleopathological diagnostic criteria for scurvy was conducted. Results: There was no clear evidence for scurvy at Con Co Ngua and a high burden of scurvy was present at Man Bac (>79% diagnosed with probable scurvy). Scurvy levels were high across all non-adult ages at Man Bac indicating significant burden throughout childhood and adolescence. Conclusions: No scurvy at Con Co Ngua is consistent with widely available food sources at the peak of the Holocene thermal maximum. High levels of scurvy at Man Bac corresponds with decreased dietary diversity, high pathogen load, and increased population stress with the transition to agriculture around the time of the 4.2 ka desertification event. Significance: This is the first systematic population-level non-adult investigation of specific nutritional disease in MSEA and demonstrates an increase in nutritional stress during the Neolithic transition in northern Vietnam. Limitations: Subperiosteal new bone deposits can be due to normal growth in infants and young children, therefore, identification of scurvy in children under the age of 4 years needs to be considered critically. Suggestions for Further Research: Further work in diagnosing specific nutritional disease in other non-adult cohorts throughout MSEA is required

    Forager and farmer evolutionary adaptations to malaria evidenced by 7000 years of thalassemia in Southeast Asia

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    Acknowledgements We would like to thank Dr. Ngo Anh Son, Mr. Bui Van Khanh and Ms. Nellissa Ling for their assistance with the radiographs. We are grateful to Dr. Dr. Nguyen Gia Doi for permission to extract histological samples. This work was supported by a National Geographic Early Career Grant (EC-54332R-18);Royal Society of New Zealand Skinner Fund Grant; University of Otago Doctoral Scholarship; Australian Research Council DP110101097 and FT120100299. Histologicalprocessing was funded by the Australian Research Council (DE190100068).Peer reviewedPublisher PD

    Studying Magnetic Fields and Dust in M17 Using Polarized Thermal Dust Emission Observed by SOFIA/HAWC

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    We report on the highest spatial resolution measurement to date of magnetic fields (B-fields) in M17 using thermal dust polarization measurements taken by SOFIA/HAWC+ centered at a wavelength of 154 μm. Using the Davis–Chandrasekhar–Fermi method, in which the polarization angle dispersion calculated using the structure function technique is the quantity directly observed by SOFIA/HAWC+, we found the presence of strong B-fields of 980 ± 230 and 1665 ± 885 μG in the lower-density M17-N and higher-density M17-S regions, respectively. The B-field morphology in M17-N possibly mimics the fields in gravitationally collapsing molecular cores, while in M17-S the fields run perpendicular to the density structure. M17-S also displays a pillar feature and an asymmetric large-scale hourglass-shaped field. We use the mean B-field strengths to determine Alfvénic Mach numbers for both regions, finding that B-fields dominate over turbulence. We calculate the mass-to-flux ratio, λ, finding λ = 0.07 for M17-N and 0.28 for M17-S. These subcritical λ values are consistent with the lack of massive stars formed in M17. To study dust physics, we analyze the relationship between dust polarization fraction, p, emission intensity, I, gas column density, N(H2), polarization angle dispersion function, S, and dust temperature, T d. p decreases with intensity as I −α with α = 0.51. p tends to first increase with T d, but then decreases at higher T d. The latter feature, seen in M17-N at high T d when N(H2) and S decrease, is evidence of the radiative torque disruption effect

    Fibronectin rescues estrogen receptor α from lysosomal degradation in breast cancer cells

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    Estrogen receptor α (ERα) is expressed in tissues as diverse as brains and mammary glands. In breast cancer, ERα is a key regulator of tumor progression. Therefore, understanding what activates ERα is critical for cancer treatment in particular and cell biology in general. Using biochemical approaches and superresolution microscopy, we show that estrogen drives membrane ERα into endosomes in breast cancer cells and that its fate is determined by the presence of fibronectin (FN) in the extracellular matrix; it is trafficked to lysosomes in the absence of FN and avoids the lysosomal compartment in its presence. In this context, FN prolongs ERα half-life and strengthens its transcriptional activity. We show that ERα is associated with β1-integrin at the membrane, and this integrin follows the same endocytosis and subcellular trafficking pathway triggered by estrogen. Moreover, ERα+ vesicles are present within human breast tissues, and colocalization with β1-integrin is detected primarily in tumors. Our work unravels a key, clinically relevant mechanism of microenvironmental regulation of ERα signaling.Fil: Sampayo, Rocío Guadalupe. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Toscani, Andrés Martin. Universidad Nacional de Luján; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Rubashkin, Matthew G.. University of California; Estados UnidosFil: Thi, Kate. Lawrence Berkeley National Laboratory; Estados UnidosFil: Masullo, Luciano Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Violi, Ianina Lucila. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias "Elizabeth Jares Erijman"; ArgentinaFil: Lakins, Jonathon N.. University of California; Estados UnidosFil: Caceres, Alfredo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Hines, William C.. Lawrence Berkeley National Laboratory; Estados UnidosFil: Coluccio Leskow, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad Nacional de Luján; ArgentinaFil: Stefani, Fernando Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Chialvo, Dante Renato. Universidad de Buenos Aires; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología. Centro Internacional de Estudios Avanzados; ArgentinaFil: Bissell, Mina J.. Lawrence Berkeley National Laboratory; Estados UnidosFil: Weaver, Valerie M.. University of California; Estados UnidosFil: Simian, Marina. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentin

    User Manual: Plastic pollution assessment methodologies suitability toolkit (PLAST)

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    PLAST is a Microsoft Excel VBA tool designed to characterize and compare plastic pollution assessment methodologies to suggest the most suitable options based on a user's requirements. The user manual details the aim, installation, method, and use of the toolkit
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