The COBE DIRBE Point Source Catalog

We present the COBE DIRBE Point Source Catalog, an all-sky catalog containing infrared photometry in 10 bands from 1.25 microns to 240 microns for 11,788 of the brightest near and mid-infrared point sources in the sky. Since DIRBE had excellent temporal coverage (100 - 1900 independent measurements per object during the 10 month cryogenic mission), the Catalog also contains information about variability at each wavelength, including amplitudes of variation observed during the mission. Since the DIRBE spatial resolution is relatively poor (0.7 degrees), we have carefully investigated the question of confusion, and have flagged sources with infrared-bright companions within the DIRBE beam. In addition, we filtered the DIRBE light curves for data points affected by companions outside of the main DIRBE beam but within the `sky' portion of the scan. At high Galactic latitudes (|b| > 5 degrees), the Catalog contains essentially all of the unconfused sources with flux densities greater than 90, 60, 60, 50, 90, and 165 Jy at 1.25, 2.2, 3.5, 4.9, 12, and 25 microns, respectively, corresponding to magnitude limits of approximately 3.1, 2.6, 1.7, 1.3, -1.3, and -3.5. At longer wavelengths and in the Galactic Plane, the completeness is less certain because of the large DIRBE beam and possible contributions from extended emission. The Catalog also contains the names of the sources in other catalogs, their spectral types, variability types, and whether or not the sources are known OH/IR stars. We discuss a few remarkable objects in the Catalog. [abridged]Comment: Accepted for publication in the Astrophysical Journal Supplement. The full tables are available at http://www.etsu.edu/physics/bsmith/dirbe

Dissection of a functional interaction between the DNA translocase, FtsK, and the XerD recombinase

Successful bacterial circular chromosome segregation requires that any dimeric chromosomes, which arise by crossing over during homologous recombination, are converted to monomers. Resolution of dimers to monomers requires the action of the XerCD site-specific recombinase at dif in the chromosome replication terminus region. This reaction requires the DNA translocase, FtsK(C), which activates dimer resolution by catalysing an ATP hydrolysis-dependent switch in the catalytic state of the nucleoprotein recombination complex. We show that a 62-amino-acid fragment of FtsK(C) interacts directly with the XerD C-terminus in order to stimulate the cleavage by XerD of BSN, a dif-DNA suicide substrate containing a nick in the ‘bottom’ strand. The resulting recombinase–DNA covalent complex can undergo strand exchange with intact duplex dif in the absence of ATP. FtsK(C)-mediated stimulation of BSN cleavage by XerD requires synaptic complex formation. Mutational impairment of the XerD–FtsK(C) interaction leads to reduction in the in vitro stimulation of BSN cleavage by XerD and a concomitant deficiency in the resolution of chromosomal dimers at dif in vivo, although other XerD functions are not affected

Working with and for social enterprises: the role of the volunteer ethnographer

Purpose – This paper considers the specific opportunities and challenges of engaging in ethnographic research with organisations in which the researcher participates as a volunteer ethnographer. Design/methodology/approach – The findings in this paper are based on four years of ethnographic research within a social enterprise. Findings – This paper finds that there are significant benefits of the role of the volunteer ethnographer and suggests ways to address some of the challenges. Research limitations/implications – As the field of social enterprise and ethnography grows and researchers engage with methodological discussions about participant observation, the authors suggest that attention should also be paid to the specifics of the role of the volunteer ethnographer. Originality/value – There is growing interest in the use of ethnography in social enterprises. This paper offers unique insight into how this methodology has been applied in the context of self-reliant groups and the importance of the engaging with discussion about the specific role of the volunteer ethnographer

Contestable adulthood: variability and disparity in markers for negotiating the transition to adulthood

Recent research has identified a discreet set of subjective markers that are seen as characterizing the transition to adulthood. The current study challenges this coherence by examining the disparity and variability in young people’s selection of such criteria. Four sentence-completion cues corresponding to four differentcontexts in which adult status might be contested were given to 156 British 16- to 17-year-olds. Their qualitative responses were analyzed to explore patterns whilst capturing some of their richness and diversity. An astonishing amount of variability emerged, both within and between cued contexts.The implications of this variability for how the transition to adulthood is experienced are explored. The argument is made that markers of the transition to adulthood are not merely reflective of the bio–psycho–social development of young people. Rather, adulthood here is seen as an essentially contested concept,located within the discursive interactional environment in which young people participate

Launching AmeriCorps: First-Year Implementation of the National and Community Service Trust Act of 1993

The National and Community Service Trust Act of 1993 spurred the creation and expansion of national service activities throughout the US, relying on the states to determine how best to implement programs locally. P/PV undertook a long-term study to document this process, paying particular attention to the nature and progress of the federal-state relationship that the Act employed to get programs up and running quickly throughout the country. This report chronicles the first year of implementation, drawing on extensive interviews with key staff members of the Corporation for National Service, state commission heads and board members, and on observations of implementation activities in nine of the participating states. A close review of developments at both the policy and implementation levels reflects the challenges and opportunities presented by the joint federal-state approach, as well as the extent to which states were able to get programs up and running quickly to satisfy this ambitious legislative mandate

Synthesising Contextually Appropriate Intonation in Limited Domains

We describe a method of synthesising contextually appropriate intonation with limited domain unit selection voices. The method enables the natural language generation component of a dialogue system to specify its intonation choices via APML, an XML-based markup language. In a pilot study, we built an APML-aware limited domain voice for use in flight information dialogues, and carried out a perception experiment comparing the APML voice to a default version built using the same recordings without the additional structure. The intonation produced by the APML voice was judged significantly more contextually appropriate than that of the default voice. These results justified building a second voice with a much larger vocabulary, using an automated script generation algorithm

Steric Hindrance as a Factor in the Hydrolytic Stability of Aromatic Ketimines

A comparison of the velocities of hydrolysis of the 2-, the 3- and the 4-methyl diphenyl ketimine hydrochlorides, in which the velocity of the first is very much slower than either of the other two, suggests steric hindrance. The very slow rate of hydrolysis of 2, 4, 6-trihydroxy diphenyl ketimine hydrochloride has been reported by one of us. This slow rate may be accounted for on the basis of the multiple opportunities for tautomerism involving the very stable enamine forms. We have recently found 2-methyl, 4, 6-dihydroxy di phenyl (orcinyl phenyl) ketimine hydrochloride to be even more slowly hydrolyzed. It would appear here that the steric hindrance effect outweighs the possible enamine tautomerism