184 research outputs found

    Tentative detection of ethylene glycol toward W51/e2 and G34.3+0.2

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    How complex organic - and potentially prebiotic - molecules are formed in regions of low- and high-mass star-formation remains a central question in astrochemistry. In particular, with just a few sources studied in detail, it is unclear what role environment plays in complex molecule formation. In this light, a comparison of relative abundances of related species between sources might be useful to explain observed differences. We seek to measure the relative abundance between three important complex organic molecules, ethylene glycol ((CH2_2OH)2_2), glycolaldehyde (CH2_2OHCHO) and methyl formate (HCOOCH3_3), toward high-mass protostars and thereby provide additional constraints on their formation pathways. We use IRAM 30-m single dish observations of the three species toward two high-mass star-forming regions - W51/e2 and G34.3+0.2 - and report a tentative detection of (CH2OH)2 toward both sources. Assuming that (CH2_2OH)2_2, CH2_2OHCHO and HCOOCH3_3 spatially coexist, relative abundance ratios, HCOOCH3_3/(CH2_2OH)2_2, of 31 and 35 are derived for G34.3+0.2 and W51/e2, respectively. CH2_2OHCHO is not detected, but the data provide lower limits to the HCOOCH3_3/CH2_2OHCHO abundance ratios of ≥\ge193 for G34.3+0.2 and ≥\ge550 for W51/e2. A comparison of these results to measurements from various sources in the literature indicates that the source luminosities may be correlated with the HCOOCH3_3/(CH2_2OH)2_2 and HCOOCH3_3/CH2_2OHCHO ratios. This apparent correlation may be a consequence of the relative timescales each source spend at different temperatures-ranges in their evolution. Furthermore, we obtain lower limits to the ratio of (CH2_2OH)2_2/CH2OHCHO for G34.3+0.2 (≥\ge6) and W51/e2 (≥\ge16). This result confirms that a high (CH2_2OH)2_2/CH2_2OHCHO abundance ratio is not a specific property of comets, as previously speculated.Comment: Accepted for publication by A&

    The Collaborative Business Intelligence Ontology (CBIOnt)

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    In the current era, many disciplines are seen devoted towards ontology development for their domains with the intention of creating, disseminating and managing resource descriptions of their domain knowledge into machine understandable and processable manner. Ontology construction is a difficult group activity that involves many people with the different expertise. Generally, domain experts are not familiar with the ontology implementation environments and implementation experts do not have all the domain knowledge. We have designed Collaborative Business Intelligence Ontology (CBIOnt) for BI4People project. In this paper, we present CBIOnt that is OWL 2 DL ontology for the description of collaborative session between different collaborators working together on the business intelligent platform. As the collaborative session between various collaborators belongs to some collaborative form, phase and research aspect, therefore CBIOnt captures this knowledge along with the collaborative session content (comments, questions, answers, etc.) so that one can inference various types of information stored on ontologies when required. In addition, it stores the location and temporal-spatial information about the collaboration held between collaborators. We believe CBIOnt serves as a formal framework for dealing with the collaborative session taken place among collaborators on the semantic Web

    Evidence for DCO+ as a probe of ionization in the warm disk surface

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    In this Letter we model the chemistry of DCO+^{+} in protoplanetary disks. We find that the overall distribution of the DCO+^{+} abundance is qualitatively similar to that of CO but is dominated by thin layer located at the inner disk surface. To understand its distribution, we investigate the different key gas-phase deuteration pathways that can lead to the formation of DCO+^{+}. Our analysis shows that the recent update in the exothermicity of the reaction involving CH2_2D+^{+} as a parent molecule of DCO+^{+} favors deuterium fractionation in warmer conditions. As a result the formation of DCO+^{+} is enhanced in the inner warm surface layers of the disk where X-ray ionization occurs. Our analysis points out that DCO+^{+} is not a reliable tracer of the CO snow line as previously suggested. We thus predict that DCO+^{+} is a tracer of active deuterium and in particular X-ray ionization of the inner disk.Comment: Accepted for publication in the Astrophysical Journal Letters (ApJL). 11 pages, 5 figure

    A Reference Model for Collaborative Business Intelligence Virtual Assistants

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    Collaborative Business Analysis (CBA) is a methodology that involves bringing together different stakeholders, including business users, analysts, and technical specialists, to collaboratively analyze data and gain insights into business operations. The primary objective of CBA is to encourage knowledge sharing and collaboration between the different groups involved in business analysis, as this can lead to a more comprehensive understanding of the data and better decision-making. CBA typically involves a range of activities, including data gathering and analysis, brainstorming, problem-solving, decision-making and knowledge sharing. These activities may take place through various channels, such as in-person meetings, virtual collaboration tools or online forums. This paper deals with virtual collaboration tools as an important part of Business Intelligence (BI) platform. Collaborative Business Intelligence (CBI) tools are becoming more user-friendly, accessible, and flexible, allowing users to customize their experience and adapt to their specific needs. The goal of a virtual assistant is to make data exploration more accessible to a wider range of users and to reduce the time and effort required for data analysis. It describes the unified business intelligence semantic model, coupled with a data warehouse and collaborative unit to employ data mining technology. Moreover, we propose a virtual assistant for CBI and a reference model of virtual tools for CBI, which consists of three components: conversational, data exploration and recommendation agents. We believe that the allocation of these three functional tasks allows you to structure the CBI issue and apply relevant and productive models for human-like dialogue, text-to-command transferring, and recommendations simultaneously. The complex approach based on these three points gives the basis for virtual tool for collaboration. CBI encourages people, processes, and technology to enable everyone sharing and leveraging collective expertise, knowledge and data to gain valuable insights for making better decisions. This allows to respond more quickly and effectively to changes in the market or internal operations and improve the progress

    Data Lakes for Digital Humanities

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    Traditional data in Digital Humanities projects bear various formats (structured, semi-structured, textual) and need substantial transformations (encoding and tagging, stemming, lemmatization, etc.) to be managed and analyzed. To fully master this process, we propose the use of data lakes as a solution to data siloing and big data variety problems. We describe data lake projects we currently run in close collaboration with researchers in humanities and social sciences and discuss the lessons learned running these projects.Comment: Data and Digital Humanities Trac

    Les quotas: levier ou frein au déroulement des carrières des femmes? Analyse suite à une enquête préliminaire dans le cas de l'enseignement supérieur et la recherche en France dans le domaine de l'informatique

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    This paper presents the preliminary results of a qualitative survey on the implementation of quotas policies, in the context of higher education and research in France, in the field of computer science specifically. Beyond the theoretical controversy over quotas, it is a question of diving into the heart of an environment that we can describe as specific (and of which we will draw some of the specificities), to collect the experience, the words of women, who are computer scientists in the academic environment, in relation to quotas. The main idea is to question the quotas implementation in order to study in which sense these quotas can indeed lead to more professional equality, but also to study the context in which they can slow down this professional equality

    Infalling-Rotating Motion and Associated Chemical Change in the Envelope of IRAS 16293-2422 Source A Studied with ALMA

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    We have analyzed rotational spectral line emission of OCS, CH3OH, HCOOCH3, and H2CS observed toward the low-mass Class 0 protostellar source IRAS 16293-2422 Source A at a sub-arcsecond resolution (~0".6 x 0".5) with ALMA. Significant chemical differentiation is found at a 50 AU scale. The OCS line is found to well trace the infalling-rotating envelope in this source. On the other hand, the CH3OH and HCOOCH3 distributions are found to be concentrated around the inner part of the infalling-rotating envelope. With a simple ballistic model of the infalling-rotating envelope, the radius of the centrifugal barrier (a half of the centrifugal radius) and the protostellar mass are evaluated from the OCS data to be from 40 to 60 AU and from 0.5 to 1.0 Msun, respectively, assuming the inclination angle of the envelope/disk structure to be 60 degrees (90 degrees for the edge-on configuration). Although the protostellar mass is correlated with the inclination angle, the radius of the centrifugal barrier is not. This is the first indication of the centrifugal barrier of the infalling-rotating envelope in a hot corino source. CH3OH and HCOOCH3 may be liberated from ice mantles due to weak accretion shocks around the centrifugal barrier, and/or due to protostellar heating. The H2CS emission seems to come from the disk component inside the centrifugal barrier in addition to the envelope component. The centrifugal barrier plays a central role not only in the formation of a rotationally-supported disk but also in the chemical evolution from the envelope to the protoplanetary disk
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