Networks of corporate power revisited

This paper examines developments through the quarter century since the publication of Stokman, Ziegler and Scott's (1985) iconic ten-nation study of the structure of interlocking directorships. The surprising decline of research in the area following the publication of Networks of Corporate Power is in part testimony to the rigour of the comparative methods used, raising the standard of evidence required for subsequent director interlock studies. But it also reflected a critical weakness in director interlock research to that point, the limited ability to answer what Mark Mizruchi has called the “So what?” question. While replicated studies found clear structures in director interlocks, varying from country to country, and there was some speculative fit with the distinctive political economies of these countries, there was little evidence of any effect of these structures on firm performance or activity. The more recent resurgence in director interlock research is in some ways rooted in a second generation of the original drivers; the ready availability of now large masses of data on firm governance and firm level performance and further advances in social network analytical techniques. Where Stokman and his colleagues manually compiled lists of directors scoured from company reports, these data are now routinely collected and compiled in accessible databases by government agencies and business information services in many countries. And there has been a gradual accumulation of advances in addressing the “so what” question

Networks of corporate power revisited

This paper examines developments through the quarter century since the publication of Stokman, Ziegler and Scott's (1985) iconic ten-nation study of the structure of interlocking directorships. The surprising decline of research in the area following the publication of Networks of Corporate Power is in part testimony to the rigour of the comparative methods used, raising the standard of evidence required for subsequent director interlock studies. But it also reflected a critical weakness in director interlock research to that point, the limited ability to answer what Mark Mizruchi has called the “So what?” question. While replicated studies found clear structures in director interlocks, varying from country to country, and there was some speculative fit with the distinctive political economies of these countries, there was little evidence of any effect of these structures on firm performance or activity. The more recent resurgence in director interlock research is in some ways rooted in a second generation of the original drivers; the ready availability of now large masses of data on firm governance and firm level performance and further advances in social network analytical techniques. Where Stokman and his colleagues manually compiled lists of directors scoured from company reports, these data are now routinely collected and compiled in accessible databases by government agencies and business information services in many countries. And there has been a gradual accumulation of advances in addressing the “so what” question

Macroalgal-Associated Dinoflagellates Belonging to the Genus Symbiodinium in Caribbean Reefs

Coral-algal symbiosis has been a subject of great attention during the last two decades in response to global coral reef decline. However, the occurrence and dispersion of free-living dinoflagellates belonging to the genus Symbiodinium are less documented. Here ecological and molecular evidence is presented demonstrating the existence of demersal free-living Symbiodinium populations in Caribbean reefs and the possible role of the stoplight parrotfish (Sparisoma viride) as Symbiodinium spp. dispersers. Communities of free-living Symbiodinium were found within macroalgal beds consisting of Halimeda spp., Lobophora variegata, Amphiroa spp., Caulerpa spp. and Dictyota spp. Viable Symbiodinium spp. cells were isolated and cultured from macroalgal beds and S. viride feces. Further identification of Symbiodinium spp. type was determined by length variation in the Internal Transcribed Spacer 2 (ITS2, nuclear rDNA) and length variation in domain V of the chloroplast large subunit ribosomal DNA (cp23S-rDNA). Determination of free-living Symbiodinium and mechanisms of dispersal is important in understanding the life cycle of Symbiodinium spp

The Effects of PC-Based Laboratories on Student Learning

The Department of Chemistry at Western Kentucky University recently incorporated a net-worked MeasureNet data acquisition and analysis system into in the second semester General Chemistry laboratories. Our investigation team has conducted a study to evaluate the effects of the MeasureNet system on student learning and performance on a Beer\u27s Law laboratory. We focused on two phenomena: the effect of the MeasureNet system on 1) student learning of specific content material and 2) student interest in chemistry and science in general. The study involved a MeasureNet system group (employing a UV-Vis spectrometer and colorimeters) and a control group (employing traditional Spectronic 20D instruments). Pre- and post-assessments were performed using written surveys, one-on-one student interviews and lab practical tasks. Results from the study indicating changes in student baseline knowledge relating to Beer\u27s Law and student comfort level in performing measurements and analysis will be presented

The Effects of a Networked Data Acquisition System on Student Learning in General Chemistry Laboratories

We have recently incorporated a networked data acquisition and analysis system into in our second semester general chemistry laboratories. Our investigation team has conducted a study to evaluate the effects of the networked data acquisition system on student performance on a Beer\u27s Law laboratory. We focused on two specific phenomena: the effect of the networked data acquisition system on 1) student learning of specific content material and 2) student comfort level with laboratory work and data analysis. The study involved a networked data acquisition group (employing a UV-Vis spectrometer and colorimeters) and a control group (employing traditional, single wavelength spectrometers). Pre- and post-assessments were performed using written surveys, one-on-one student interviews, and lab practical tasks. Results from the study indicating changes in student baseline knowledge relating to Beer\u27s Law and student comfort level in performing measurements and analysis will be presented

Improving Anaerobic Digestion of Brewery and Distillery Spent Grains through Aeration across a Silicone Membrane

An increase in the number of independent breweries and distilleries has led to an increase in the amount of spent grains with inadequate means of disposal. One option for disposal is as feedstock for anaerobic digestion if digester stability is ensured. In this study, brewers’ spent grain and distillers’ spent grain were used as substrate for anaerobic digestion for 32 weeks. The digestate was treated by recirculation through a silicone hose located in an external tank filled with saline solution. The hose served as a permeable membrane allowing for the passage of gases. The recirculation tanks were fitted with check valves to maintain three pressure/gas regimes: 26 mm Hg N2, 26 mm Hg aeration or 100 mm Hg aeration. A fourth digester was operated with no recirculation as the control. These treatments were chosen to determine if differences in digester stability, wastewater treatment efficiency, and biogas production could be detected. A combination of dairy and swine manure was used as seeding to provide a methanogenic consortium and bicarbonate buffering. However, despite trying to provide for adequate initial bicarbonate buffering, all four digesters had low initial buffering and consequently low pH as short-chain fatty acids accumulated. After six weeks, bicarbonate buffering and pH increased as methane production increased, and short-chain fatty acids decreased. Later, despite the fluxes of O2 and N2 across the silicone membrane being very low, differences between the various treatments were noted. The pH of the digestate treated by N2 recirculation was lower than the other digesters and decreased further after distillers’ spent grain was substituted for brewers’ spent grain. Aeration at a pressure of 26 mm Hg and 100 mg Hg increased biogas production compared to other treatments but only significantly so at 100 mm Hg. These results suggest that partial purging of dissolved gases in anaerobic digestate by the small fluxes of N2 or O2 across a permeable membrane may affect digester performance

Lidar observations of ozone changes induced by subpolar air mass motion over Table Mountain, California (34.4°N)

International audienceBetween October 15 and November 8, 1988, the Goddard Space Flight Center mobile stratospheric lidar was in place at the (JPL) Table Mountain Facility (located at 34.4°N, 117.7°W) for the purpose of intercomparing with the JPL lidar permanently stationed at the observatory. During the course of the intercomparison both lidar systems detected a significant change in the vertical profile of ozone lasting for several days. An analysis of meteorological data available from the National Meteorological Center has shown this change to be dynamical in origin due to the transport of subpolar air over Table Mountain

Measurement intercomparison of the JPL and GSFC stratospheric ozone lidar systems

International audienceFor approximately one month during October and November 1988 the NASA Goddard Space Flight Center mobile lidar system was brought to the Jet Propulsion Laboratory, Table Mountain Facility, to make side-by-side measurements with the JPL lidar of stratospheric ozone concentration profiles. Measurements were made by both excimer laser DIAL systems on fifteen nights during this period. The results showed good agreement of the ozone profiles measured between 20- and 40-km altitude. This is believed to be the first reported side-by-side measurement intercomparison of two stratospheric ozone lidar systems

Trap and release of bisphenol-A, 2-naphthol, and doxepin using a 1-hexadecylamine-copper(II)-amine functionalized indium-tin-oxide electrode

An electrically controlled and renewable hydrophobic surface used to trap and release three test pollutants on an indium-tin-oxide (ITO) electrode is presented. Oxygen plasma was used to maximize the activated hydroxyl groups on the ITO surface, which were reacted with (3-aminopropyl) triethoxysilane (APTES) to create a 3-amino propyl layer. Copper(II) ions were introduced and attached to the terminal amine groups. The amine group from 1-hexadecylamine (HDA), complexed the surface-confined copper(II) ions, which resulted in terminal hexadecyl alkyl groups. The created hydrophobic surface was tested for its ability to adsorb pollutant substances, namely bisphenol-A, 2-naphthol, and doxepin. Desorption was accomplished by reducing copper(II) to copper(0) electrochemically. This led to the weakening of the metal-amine complex and the concomitant detachment of the HDA and trapped species from the ITO surface. Efficient trapping and releasing of bisphenol-A (1 ppm) was achieved with around 84% adsorption, 100% desorption (in a time course of less than 30 s), and 42-fold enrichment on the concentration. After each adsorption/desorption trial, regeneration of the hydrophobic surface was achieved by reapplication of copper(II) ions and HDA. Five cycles were successfully repeated without any significant deterioration in performance. Similar trap-and-release performance was also attained for 2-naphthol and doxepin