Monsters and Babies from the FIRST/IRAS Survey

Radio continuum emission at cm wavelengths is relatively little affected by extinction. When combined with far-infrared (FIR) surveys this provides for a convenient and unbiased method to select (radio-loud) AGN and starbursts deeply embedded in gas and dust--rich galaxies. Such radio-selected FIR samples are useful for detailed investigations of the complex relationships between (radio) galaxy and starburst activity, and to determine whether ULIRGs are powered by hidden quasars (monsters) or young stars (babies). We present the results of a large program to obtain identifications and spectra of radio-selected, optically faint IRAS/FSC objects using the FIRST/VLA 20 cm survey. These objects are all radio-`quiet' in the sense that their radio power / FIR luminosities follow the well-known radio/FIR relationship for star forming galaxies. We compare these results to a previous study by our group of a sample of radio-`loud' IRAS/FSC ULIRGs selected from the Texas 365 MHz survey. Many of these objects also show evidence for dominant, A-type stellar populations, as well as high ionization lines usually associated with AGN. These radio-loud ULIRGs have properties intermediate between those of starbursts and quasars, suggesting a possible evolutionary connection. Deep Keck spectroscopic observations of three ULIRGs from these samples are presented, including high signal-to-noise spectropolarimetry. The polarimetry observations failed to show evidence of a hidden quasar in polarized (scattered) light in the two systems in which the stellar light was dominated by A-type stars. Although observations of a larger sample would be needed to allow a general conclusion, our current data suggest that a large fraction of ULIRGs may be powered by luminous starbursts, not by hidden, luminous AGN (quasars). [abridged]Comment: 6 Pages, including 2 PostScript figures. To appear in proceedings of "Ultraluminous Galaxies: Monsters and Babies", held at Ringberg Castle, Germany, 20-26 September 199

COMMON FISHERY POLICY AND NATIONAL FISHERIES MANAGEMENT

Resource /Energy Economics and Policy,

AN ECONOMIC APPROACH TO MEASURING FISHING EFFORT: APPLICATION TO A DUTCH CUTTER FLEET

Resource /Energy Economics and Policy,

Passages in Graphs

Directed graphs can be partitioned in so-called passages. A passage P is a set of edges such that any two edges sharing the same initial vertex or sharing the same terminal vertex are both inside $P$ or are both outside of P. Passages were first identified in the context of process mining where they are used to successfully decompose process discovery and conformance checking problems. In this article, we examine the properties of passages. We will show that passages are closed under set operators such as union, intersection and difference. Moreover, any passage is composed of so-called minimal passages. These properties can be exploited when decomposing graph-based analysis and computation problems.Comment: 8 page

The Role of Small Reservoirs in Reducing Reactive N Export Via Denitrification

Reactive nitrogen (N), which harms ecosystem health, has been increasing in the biosphere, leading to higher N export to coastal ecosystems. Although man-made reservoirs can be significant sources of greenhouse gases, they can also retain N, thus reducing N export. Because many dams are relics from industrial hydropower, their removal is becoming increasingly common. It is therefore crucial to understand the ecological tradeoffs of man-made reservoirs. While previous studies have examined nutrient budgets and denitrification at inputs and outputs of large reservoirs, small reservoir dynamics remain understudied. In this study, we measured inputs and outputs of NO3 and N2 at two small coastal reservoirs and assessed reasons for changes by sampling internally within the reservoirs. We hypothesized that denitrification is high in small reservoirs due to lower dissolved oxygen. While we found evidence of denitrification in one reservoir the second reservoir showed evidence of N fixation. Fixation was evident within the reservoir where low NO3 concentrations and high algal growth occurred, suggesting that NO3 was being assimilated, limiting algal growth, and allowing the occurrence of N fixing algae. As a result, reservoirs may not always remove N, but may at times be a source of additional N. As dam removal decisions continue, the role of reservoirs in N export should be carefully considered

MNC Staffing policies for the managing director position in foreign subsidiaries : the results of an innovative research method

This research note draws the attention to the harmful consequence of a serious lack of empirical research in the field of International Human Resource Management: myth-building on the basis of one or two publications. The apparent myth of high expatriate failure rates is shortly discussed. To prevent another myth from appearing, this time in the field of staffing policies, this research note provides an empirical test of the framework proposed by Meredith Downes (1996) for making decisions about staffing foreign subsidiaries. The propositions set forward by Downes are tested using a database of nearly 1800 subsidiaries located in twenty-two different countries. Headquarters of these subsidiaries are located in nine different countries and operate in eight different industries. Although the variables suggested by Downes have a fair explanatory power, some of the specific propositions had to be rejected.management and organization theory ;

Nuclear activity and the environments of nearby radio galaxies

Much of our present understanding of galaxy evolution over a large redshift range is based on the study of samples selected on the basis of non-thermal radio emission. It is therefore necessary to understand the relationship between radio source activity and the host galaxy. Recent observations suggest that there is a connection between radio galaxy (RG) activity and radio galaxy evolution. For example, high-redshift RGs (z approx. greater than 0.7) show evidence for significant populations of young stars, and have optical continuum morphologies nearly always aligned with the radio axis (McCarthy et al. 1987; Chambers et al. 1987). This phenomenon is generally attributed to radio jet induced star formation (DeYoung 1989), but the lack of high S/N spectra of the galaxy continua, and recent detections of polarized light in a few objects make it hard to rule out other processes such as scattering or synchrotron radiation. A detailed study of the continuum light in the distant RGs is difficult as they are optically very faint. However, nearby RGs (z approx. less than 0.1) have bluer B-V colors than radio-quiet ellipticals, presumably due to the presence of young stellar populations (Smith and Heckman 1989) and several have extended UV continuum emitting regions along their radio axes (van Bruegel et al. 1985a, b, di Serego Alighieri et al. 1989), reminiscent of the alignment effect seen in the high redshift RGs. We have almost completed a continuum imaging survey of nearby (and therefore optically brighter), powerful RGs to study any possible relationships between the optical continuum light and radio source activity. In particular we are interested in (1) whether these lower redshift RGs shown any evidence of the alignment effect (in their rest-frame UV light) that is seen in the distant RGs, and (2) the effects that the radio source has on the environment of the host galaxy