Centrality in valued graphs: A measure of betweenness based on network flow

A new measure of centrality, C,, is introduced. It is based on the concept of network flows. While conceptually similar to Freeman’s original measure, Ca, the new measure differs from the original in two important ways. First, C, is defined for both valued and non-valued graphs. This makes C, applicable to a wider variety of network datasets. Second, the computation of C, is not based on geodesic paths as is C, but on all the independent paths between all pairs of points in the network

Creating a Bigger Pie? The Effects of Employee Ownership, Profit Sharing, and Stock Options on Workplace Performance

This paper uses data from NBER surveys of over 40,000 employees in hundreds of facilities in 14 firms and from employees on the 2002 and 2006 General Social Surveys to explore how shared compensation affects turnover, absenteeism, loyalty, worker effort, and other outcomes affecting workplace performance. The empirical analysis shows that shared capitalism has beneficial effects on all outcomes save for absenteeism and that it has its strongest effects on turnover, loyalty, and worker effort when it is combined with: a) high-performance work policies (employee involvement, training, and job security), b) low levels of supervision, and c) fixed wages that are at or above market level. Most workers report that cash incentives, stock options, ESOP stock, and ESPP participation motivate them to work harder. The interaction of the effects of shared capitalism with other corporate policies suggests that the various shared capitalist and other policies may operate through a latent variable, "corporate culture".

Testing the nature of S0 galaxies using planetary nebula kinematics in NGC 1023

We investigate the manner in which lenticular galaxies are formed by studying their stellar kinematics: an S0 formed from a fading spiral galaxy should display similar cold outer disc kinematics to its progenitor, while an S0 formed in a minor merger should be more dominated by random motions. In a pilot study to attempt to distinguish between these scenarios, we have measured the planetary nebula (PN) kinematics of the nearby S0 system NGC 1023. Using the Planetary Nebula Spectrograph, we have detected and measured the line-of-sight velocities of 204 candidate PNe in the field of this galaxy. Out to intermediate radii, the system displays the kinematics of a normal rotationally-supported disc system. After correction of its rotational velocities for asymmetric drift, the galaxy lies just below the spiral galaxy Tully-Fisher relation, as one would expect for a fading system. However, at larger radii the kinematics undergo a gradual but major transition to random motion with little rotation. This transition does not seem to reflect a change in the viewing geometry or the presence of a distinct halo component, since the number counts of PNe follow the same simple exponential decline as the stellar continuum with the same projected disc ellipticity out to large radii. The galaxy's small companion, NGC 1023A, does not seem to be large enough to have caused the observed modification either. This combination of properties would seem to indicate a complex evolutionary history in either the transition to form an S0 or in the past life of the spiral galaxy from which the S0 formed. More data sets of this type from both spirals and S0s are needed in order to definitively determine the relationship between these types of system.Comment: Accepted for publication in MNRAS. Version with full resolution figure 1 can be found at http://www.nottingham.ac.uk/~ppzmrm/N1023_PNS.accepted.pd

Dark-Matter Content of Early-Type Galaxies with Planetary Nebulae

We examine the dark matter properties of nearby early-type galaxies using planetary nebulae (PNe) as mass probes. We have designed a specialised instrument, the Planetary Nebula Spectrograph (PN.S) operating at the William Herschel telescope, with the purpose of measuring PN velocities with best efficiency. The primary scientific objective of this custom-built instrument is the study of the PN kinematics in 12 ordinary round galaxies. Preliminary results showing a dearth of dark matter in ordinary galaxies (Romanowsky et al. 2003) are now confirmed by the first complete PN.S datasets. On the other hand early-type galaxies with a "regular" dark matter content are starting to be observed among the brighter PN.S target sample, thus confirming a correlation between the global dark-to-luminous mass virial ratio (f_DM=M_DM/M_star) and the galaxy luminosity and mass.Comment: 5 pages, 2 figures. To appear in the proceedings of the IAU Symposium 244 "Dark Galaxies and Lost Baryons", Cardiff 25-29 June 2007, eds. J.I. Davies & M.J. Disne

Phase I Cultural Resources Investigations at Justiceburg Resevoir on the Double Mountain Fork of the Brazos River, Garza and Kent Counties, Texas Volume II

The prehistoric site descriptions are divided into three sections: Garza County, Kent County, and Isolated Finds. All sites are described fully in a telegraphic format in order to conserve space. The descriptions are organized by county in alphabetical order and in numerical order of site within each county. Information for each site 1s organized into six headings: location, description, features, cultural materials observed/collected, shovel test data, and assessment/recommendations. The determination of the percentage of the site remaining intact is based on in-field observations of the postulated original areal extent of the site versus what is still potentially intact. Assessments are based on each site\u27s individual merits and are stated in terms of eligibility for listing on the National Register of Historic Places. These assessments were made by the Project Archeologist and the Principal Investigator based on a site-by-site review. Two categories of eligibility include: potentially eligible (sites with excellent to unknown research potential) , and not eligible (sites with little or no further research potential). Research potential is derived from each site I s potential to contribute to the resolution of the questions posed in the Research Design (Chapter 5). While most of the research potential categories are reasonably clear, the unknown category should be more fully explained. Sites with unknown potential are those that are buried, lack exposed features, and failed to yield temporally or functionally diagnostic materials. The unknownII designation refers to the inability (based on extant data) to specify which research questions a site may appropriately address rather than a lack of any research potential. Assessments also may refer to exotics. This term is used to identify materials or artifacts that were imported into the local area. Included are such items as obsidian, Alibates agate, Tecovas jasper, and nonlocal ceramics. Recommendations are provided on the basis of each site\u27s assessment. These do not consider the suggested sampling strategy described in Chapter 13, Recommendations/Treatment Plan. Isolated Finds were thoroughly documented in the field and were assigned trinomial site numbers to facilitate record Jceeping; however, they are not felt to be worthy of extended descriptions for reporting purposes. Therefore, this category of sites is treated in highly abbreviated form in a separate section following the site descriptions. Information provided for Isolated Finds includes: site number, location, landform, elevation, area, description, and material type. Isolated finds are defined as any single surface artifact or feature with no associated materials or features, or surface sites with a density of cultural materials less than one item in 20 rna. These finds generally are highly disturbed, redeposited, or lack intact context. No shovel testing was done at Isolated Finds, except at sites 41GR411, 41GR482, 41GRS19, 41GRS32, 41KT46, and 41KT71, where all tests excavated were negative. Only three of these Isolated Finds are dated. These sites are considered to retain little interpretive value beyond the survey level, and none require further work. Because of this, Isolated Finds are not considered eligible for listing on the National Register of Historic Places. Finally, abbreviations are used throughout the site descriptions. Those referring to roads, distances, elevations, and cardinal directions are self-explanatory. However, two others require explanation. GRC refers to Grand River Consultants, Inc., a firm located in Grand River, Colorado, which performed limited archeological survey at Justiceburg in 1982. NRHP refers to the National Register of Historic Places; this phrase is abbreviated to save space since it must be used in the assessments of each individual site