10,632 research outputs found

    The Nature and Frequency of Outflows from Stars in the Central Orion Nebula Cluster

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    Recent Hubble Space Telescope images have allowed the determination with unprecedented accuracy of motions and changes of shocks within the inner Orion Nebula. These originate from collimated outflows from very young stars, some within the ionized portion of the nebula and others within the host molecular cloud. We have doubled the number of Herbig-Haro objects known within the inner Orion Nebula. We find that the best-known Herbig-Haro shocks originate from a relatively few stars, with the optically visible X-ray source COUP 666 driving many of them. While some isolated shocks are driven by single collimated outflows, many groups of shocks are the result of a single stellar source having jets oriented in multiple directions at similar times. This explains the feature that shocks aligned in opposite directions in the plane of the sky are usually blue shifted because the redshifted outflows pass into the optically thick Photon Dominated Region behind the nebula. There are two regions from which optical outflows originate for which there are no candidate sources in the SIMBAD data base.Comment: 152 pages, 46 figures, 7 tables. Accepted by A

    Steel heat treating: Mathematical modelling and numerical simulation of a problem arising in the automotive industry

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    We describe a mathematical model for the industrial heating and cooling processes of a steel workpiece representing the steering rack of an automobile. The goal of steel heat treating is to provide a hardened surface on critical parts of the workpiece while keeping the rest soft and ductile in order to reduce fatigue. The high hardness is due to the phase transformation of steel accompanying the rapid cooling. This work takes into account both heating-cooling stage and viscoplastic model. Once the general mathematical formulation is derived, we can perform some numerical simulations

    Analysis of transmitted HIV-1 drug resistance using 454 ultra-deep-sequencing and the DeepChek(®)-HIV system.

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    Introduction Next-generation sequencing (NGS) is capable of detecting resistance-associated mutations (RAMs) present at frequencies of 1% or below. Several studies have found that baseline low-frequency RAMs are associated with failure to first-line HAART. One major limitation to the expansion of this technology in routine diagnostics is the complexity and laboriousness integral to bioinformatics analysis. DeepChek (ABL, TherapyEdge) is a CE-marked software that allows automated analysis and resistance interpretation of NGS data. Objective To evaluate the use of 454 ultra-deep-sequencing (Roche® 454, Life Sciences; 454-UDS) and DeepChek for routine baseline resistance testing in a clinical diagnostic laboratory. Methods 107 newly diagnosed HIV-1-infected patients (subtypes: A, n=9; B, n=52; C, n=21; D, n=2; F, n=3; G, n=1; CRF01, n=7; CRF02, n=7; CRF06, n=1; CRF07, n=1; CRF10, n=1 and unassigned complex, n=2) with a median plasma viral load of 88,727 copies/mL (range: 1380–2,143,543) were tested by 454-UDS and Sanger sequencing for the detection of protease and reverse transcriptase RAMs. In addition, integrase RAMs were investigated in 57 of them. Sequence analysis and resistance interpretation were performed using DeepChek applying 1% and 20% thresholds for variant detections; filters applied were comparison between Sanger and 454-UDS, and Stanford and IAS list for resistance interpretation. Results The time elapsed from generation of raw 454 data (between 2,000–5,000 sequences/sample) to elaboration of a resistance report was approximately 10 minutes per sample, equivalent to the time required for the same process using Sanger sequencing. Four patients (3.7%) showed baseline resistance by Sanger and 454-UDS at frequencies above 20%, which affected both NRTIs (n=2) and NNRTIs (n=2). In addition, 12 patients (11.2%) showed transmitted drug resistance (TDR) by 454-UDS at frequencies below 20% affecting NRTIs (n=9), NNRTIs (n=7) and PIs (n=2). Integrase resistance was not detected at baseline by 454-UDS or Sanger sequencing. Conclusions DeepChek allowed easy and rapid analysis and interpretation of NGS data, thus facilitating the incorporation of this technology in routine diagnostics. The use of NGS considerably increased the detection rates of TDR to NRTI, NNRTIs and PIs. No transmitted resistance to integrase inhibitors was found in our population by Sanger sequencing or UDS

    A Search for "Dwarf" Seyfert Nuclei. III. Spectroscopic Parameters and Properties of the Host Galaxies

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    We have completed an optical spectroscopic survey of the nuclear regions (r < 200 pc) of a large sample of nearby galaxies. Although the main objectives of the survey are to search for low-luminosity active galactic nuclei and to quantify their luminosity function, the database can be used for a variety of other purposes. This paper presents measurements of the spectroscopic parameters for the 418 emission-line nuclei, along with a compilation of the global properties of all 486 galaxies in the survey. Stellar absorption generally poses a serious obstacle to obtaining accurate measurement of emission lines in nearby galactic nuclei. We describe a procedure for removing the starlight from the observed spectra in an efficient and objective manner. The main parameters of the emission lines (intensity ratios, fluxes, profile widths, equivalent widths) are measured and tabulated, as are several stellar absorption-line and continuum indices useful for studying the stellar population. Using standard nebular diagnostics, we determine the probable ionization mechanisms of the emission-line objects. The resulting spectral classifications provide extensive information on the demographics of emission-line nuclei in the local universe. This new catalog contains over 200 objects showing spectroscopic evidence for recent star formation and an equally large number of active galactic nuclei, including 46 which show broad H-alpha emission. These samples will serve as the basis of future studies of nuclear activity in nearby galaxies.Comment: To appear in the Astrophysical Journal Supplements. LaTex, 31 pages, plus an additional 23 figures and 5 tables. AASTex macro aaspp4.st

    Seasonal variations of carcass characteristics, meat quality and nutrition value in iberian wild red deer

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    Aim of study: The effects of hunting season (autumn vs. winter) on carcass characteristics and meat quality of Iberian wild red deer were assessed. Area of study: A total of 100 males of wild red deer of Iberian genetic line (Cervus elaphus) were hunted on Ciudad Real (south central Spain). Material and methods: Yields for shoulder (with bone), neck, backbone, loin, tenderloin, leg (with bone), short plate and flank were determined. In addition, samples of Longissimus thoracis et lumborum and Rectus abdominis muscles were collected. Then, pH48, colour measurements, chemical composition, cooking loss, Warner Bratzler shear blade, fatty acid and amino acid profiles and mineral content were analyzed. Main results: Deer hunted in autumn (n=50) had higher (p&lt;0.01) yields of shoulder, backbone and short plate and higher contents of intramuscular fat (IMF), cholesterol and K, Fe and Mn but lower (p&lt;0.001) pH48 and Na, Mg, Zn and Cu contents than deer hunted in winter (n=50). Shear force tended (p=0.05) to be lower for meat collected in autumn than for meat collected in winter. However, loin yield was 59.2% higher (p&lt;0.001) for winter than for autumn carcasses. Deer hunted in winter had higher α-linoleic acid (p&lt;0.05) and long chain n-3 polyunsaturated (p&lt;0.001) percentages than deer hunted in autumn Research highlights: Autumn hunting is recommended to obtain carcasses with higher yields of shoulder, backbone and short plate and meat with higher IMF. Conversely, winter hunting is advisable for higher loin yield and for a profile richer in polyunsaturated fatty acids

    Infrared spectral fingerprint of neutral and charged endo- and exohedral metallofullerenes

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    Small metal-containing molecules have been detected and recognized as one of the hybrid species efficiently formed in space; especially in the circumstellar envelopes of evolved stars. It has been predicted also that more complex hybrid species like those formed by metals and fullerenes (metallofullerenes) could be present in such circumstellar environments. Recently, quantum-chemical simulations of metallofullerenes have shown that they are potential emitters contributing to the observed mid-IR spectra in the fullerene-rich circumstellar environments of different types of evolved stars. Here we present the individual simulated mid-IR (~5-50 um) spectra of twenty-eight metallofullerene species; both neutral and charged endo- and exohedral metallofullerenes for seven different metals (Li, Na, K, Ca, Mg, Ti, and Fe) have been considered. The changes induced by the metal-C60 interaction on the intensity and position of the spectral features are highlighted using charge density difference maps and electron density partitioning. Our calculations identify the fundamental IR spectral regions where, depending on the metal binding nature, there should be a major spectral contribution from each of the metallofullerenes. The metallofullerenes IR spectra are made publicly available to the astronomical community, especially James Webb Space Telescope users, for comparisons that could eventually lead to the detection of these species in space.Comment: Accepted for publication in The Astrophysical Journal Supplement Series on 19 September 2023 (in press) (13 pages, 7 figures, and 1 table

    Modelling Tropical Deforestation: A Comparison of Approaches

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    International audienceTropical deforestation, as an important factor in global change, is a topic that recently has received considerable attention. GIS-based spatially explicit models that intend to predict the location of land use/cover change (LUCC) can help scientists and policy makers to understand, anticipate and possibly prevent the adverse effects of land-use change. There are many approaches and softwares to model LUCC such as CLUE-S, DINAMICA GEOMOD and IDRISI. This study intends to compare these four modelling approaches. First, a review of methods and tools employed by each software to carry out the simulation was done. Then, the four packages were applied to a "virtual" case which involves a map of deforestation, which comprises two types of deforestation (forest to shifting agriculture and forest to pasture lands), along with several explanatory variables (drivers). Deforestation was modelled using the four approaches and the output maps were compared
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