1,431 research outputs found

    SCUBA Observations of High Redshift Radio Galaxies

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    High redshift radio galaxies (HzRGs) are key targets for studies of the formation and evolution of massive galaxies. The role of dust in these processes is uncertain. We have therefore observed the dust continuum emission from a sample of z > 3 radio galaxies with the SCUBA bolometer array. We confirm and strengthen earlier results, that HzRGs are massive starforming systems and that submillimeter detection rate appears to be primarily a strong function of redshift. We also observed HzRG-candidates which have sofar eluded spectroscopic redshift determination. Four of these have been detected, and provide evidence that they may be extremely obscured radio galaxies, possibly in an early stage of their evolution.Comment: 6 Pages, including 7 PostScript figures. To appear in the proceedings of the conference "Radio Galaxies: Past, present and future", Leiden, 11-15 Nov 2002, eds. M. Jarvis, et a

    Щодо питання про форму трудового договору

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    Розкриваються особливості форм трудового договору, дається її визначення, підкреслюється важливість письмової форми трудового договору, її перевага перед усною. Аналізуються точки зору провідних науковців Європи в галузі трудового права.Расскрываются особенности форм трудового договора, дается ее определение, подчеркивается важность письменной формы трудового договора, ее преимущество перед устной, анализируются точки зрения ведущих ученых Европы в отрасли трудо­вого права.The author has researched the specific features of the contract labour, has given its defini­tion, pointed out the importance of the written form of this contract, this type of the contract has been analyzed from the point of view of the leading scientists of Europe in the field of labour law

    Application of association rules to determine building typological classes for seismic damage predictions at regional scale. The case study of Basel

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    Assessing seismic vulnerability at large scales requires accurate attribution of individual buildings to more general typological classes that are representative of the seismic behavior of the buildings sharing same attributes. One-by-one evaluation of all buildings is a time-and-money demanding process. Detailed individual evaluations are only suitable for strategic buildings, such as hospitals and other buildings with a central role in the emergency post-earthquake phase. For other buildings simplified approaches are needed. The definition of a taxonomy that contains the most widespread typological classes as well as performing the attribution of the appropriate class to each building are central issues for reliable seismic assessment at large scales. A fast, yet accurate, survey process is needed to attribute a correct class to each building composing the urban system. Even surveying buildings with the goal to determine classes is not as time demanding as detailed evaluations of each building, this process still requires large amounts of time and qualified personnel. However, nowadays several databases are available and provide useful information. In this paper, attributes that are available in such public databases are used to perform class attribution at large scales based on previous data-mining on a small subset of an entire city. The association-rule learning (ARL) is used to find links between building attributes and typological classes. Accuracy of wide spreading these links learned on <250 buildings of a specific district is evaluated in terms of class attribution and seismic vulnerability prediction. By considering only three attributes available on public databases (i.e., period of construction, number of floors, and shape of the roof) the time needed to provide seismic vulnerability scenarios at city scale is significantly reduced, while accuracy is reduced by <5%

    Teasing apart retrieval and encoding interference in the processing of anaphors

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    Two classes of account have been proposed to explain the memory processes subserving the processing of reflexive-antecedent dependencies. Structure-based accounts assume that the retrieval of the antecedent is guided by syntactic tree-configurational information without considering other kinds of information such as gender marking in the case of English reflexives. By contrast, unconstrained cue-based retrieval assumes that all available information is used for retrieving the antecedent. Similarity-based interference effects from structurally illicit distractors which match a non-structural retrieval cue have been interpreted as evidence favoring the unconstrained cue-based retrieval account since cue-based retrieval interference from structurally illicit distractors is incompatible with the structure-based account. However, it has been argued that the observed effects do not necessarily reflect interference occurring at the moment of retrieval but might equally well be accounted for by interference occurring already at the stage of encoding or maintaining the antecedent in memory, in which case they cannot be taken as evidence against the structure-based account. We present three experiments (self-paced reading and eye-tracking) on German reflexives and Swedish reflexive and pronominal possessives in which we pit the predictions of encoding interference and cue-based retrieval interference against each other. We could not find any indication that encoding interference affects the processing ease of the reflexive-antecedent dependency formation. Thus, there is no evidence that encoding interference might be the explanation for the interference effects observed in previous work. We therefore conclude that invoking encoding interference may not be a plausible way to reconcile interference effects with a structure-based account of reflexive processing

    Evolution of the Lyman-alpha Halos around High-Redshift Radio Galaxies

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    We have obtained the first constraints on extended Ly-alpha emission at z ~ 1 in a sample of five radio galaxies. We detect Ly-alpha emission from four of the five galaxies. The Ly-alpha luminosities range from 0.1 - 4 times 10^43 erg/s and are much smaller than those observed for halos around higher redshift radio galaxies. If the z ~ 1 radio galaxies are the descendents the z >~ 2 radio galaxies, then their Ly-alpha luminosities evolve strongly with redshift as ~(1+z)^5. There do not appear to be strong correlations between other parameters, such as radio power, suggesting that this observed evolution is real and not an observational artifact or secondary correlation. We speculate that this evolution of luminous halos may be due to gas depletion (as gas cools, settles, and forms stars) accompanied by an overall rise in the mean gas temperature and a decrease in specific star-formation rate in and around these massive galaxies.Comment: 5 pages, 4 figures, published in ApJ Letters, 694, L31-35 March 20 200

    Policing vulnerability through building community connections

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    Most people who come into contact with the Police Service can be described, in some way or other, as vulnerable. Victims, offenders, witnesses, and bystanders are all exposed to social conflict and attempts by the police to restore order. Thus, while vulnerability is context-specific it is largely defined via deficit frameworks that view individuals and groups as marginalized or disadvantaged and requiring immediate intervention. This framework is expensive, risk-averse, and often counter-productive for police and associated agencies. The policy push for demand reduction amongst policing agencies offers an opportunity to re-evaluate this approach and to identify and mobilize local assets that can support vulnerable populations. This article draws on the literature on addictions and recovery to explore the networks of support available to vulnerable populations and the potential mechanisms this presents for the development of assertive linkages, community capacity, and self-policing

    The Discovery of a Large Lyman-alpha+HeII Nebula at z~1.67: A Candidate Low Metallicity Region?

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    We have discovered a ~45 kpc Lya nebula (or Lya ``blob'') at z~1.67 which exhibits strong, spatially-extended HeII emission and very weak CIV and CIII] emission. This is the first spatially-extended Lya+HeII emitter observed and the lowest redshift Lya blob yet found. Strong Lya and HeII-1640 emission in the absence of metal lines has been proposed as a unique observational signature of primordial galaxy formation (e.g., from gravitational cooling radiation or Population III star formation), but no convincing examples of spatially-extended Lya+HeII emitters have surfaced either in Lya-emitting galaxy surveys at high redshifts (z > 4) or in studies of Lya nebulae at lower redshifts. From comparisons with photoionization models, we find that the observed line ratios in this nebula are consistent with low metallicity gas (Z < 10^-2 - 10^-3 Z_sun), but that this conclusion depends on the unknown ionization parameter of the system. The large HeII equivalent width (~37+/-10A) and the large HeII/Lya ratio (0.12+/-0.04) suggest that the cloud is being illuminated by a hard ionizing continuum, either an AGN or very low metallicity stars, or perhaps powered by gravitational cooling radiation. Thus far there is no obvious sign of a powerful AGN in or near the system, so in order to power the nebula while remaining hidden from view even in the mid-infrared, the AGN would need to be heavily obscured. Despite the strong Lya+HeII emission, it is not yet clear what is the dominant power source for this nebula. The system therefore serves as an instructive example of how the complexities of true astrophysical sources will complicate matters when attempting to use a strong Lya+HeII signature as a unique tracer of primordial galaxy formation.Comment: Accepted for publication in ApJ; emulateapj format, 17 pages, 7 figures, 3 tables; updated coordinate
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