Knowledge,influence, and firm-level change: A geographic analysis of board membership associated with Canada’s growing and declining businesses

Clarification of the factors that drive business expansion and contraction is among the most important topics that can be addressed by research in economic geography and related disciplines. This study analyzes the development of Canadian business by examining the connection between firm-level growth and decline and elite knowledge and influence connections that Canadian businesses use to link themselves to other corporations and cities nationally and globally. The research focuses on the inter-firm and inter-city linkages embodied in the boards of directors of Canada’s leading corporations. Corporate directorships have an important geographic dimension, as firms invite people from a variety of places and backgrounds to serve on their boards. This study finds that board member selection practices among Canadian firms can be linked directly to business growth and decline. Benchmarking board composition against firm expansion and decline in terms of inflation-adjusted annual revenue change over the 1991–2006 period, this study shows that growing Canadian firms are associated with directors from a much broader range of national and international cities than firms that experienced decline over the same period. Firm growth in Canada thus appears to be related to boards encompassing diverse members from national and international locations, while firm decline appears to be associated with boards including more local and regional members. The conclusion interprets the implications of board member diversity and suggests that broadly-based boards can play a role in encouraging firm growth through access to elite knowledge and influence networks.     

Seasonal metal remobilization in the sediments of Great Bay,New Hampshire

Concentrations of dissolved iron, manganese, molybdenum, copper, and organic carbon (DOC) were measured in the pore waters from surficial sediments of a temperate estuary to delineate seasonal metal remobilization from 1978 through 1980. Iron and DOC data were collected for 31 months and covaried inversely and exponentially. Iron dissolution occurred during the spring and during periods of active bioturbation with concentrations as high as 18 mg 1^?1. Iron values were low during winter due to oxidation to ferric oxides. The lack of active bioturbation during the summer of 1978 allowed for the nearly complete removal of iron as a monosulfide precipitate. However, bioturbation resumed during the summer of 1979 and 1980 and dissolved iron concentrations as high as 10 mg 1^?1 were observed at those times. The iron and DOC data were a qualitative measure of bioturbation activity. Dissolved manganese, molybdenum, and copper data were collected for 18 months during 1978 and 1979. All three metals displayed spring maxima covariate with iron, suggesting that they behaved chemically like iron and/or were associated with iron- or manganese-rich phases during this time of the year. In general, manganese and molybdenum varied temporally with iron while copper concentrations mimicked iron variations only during the spring.     

Granta MIST

The magnetosphere, ionosphere and solar–terrestrial physics community gathered at Selwyn College, University of Cambridge, for three days between Tuesday 5 April and Thursday 7 April 2005. Neil Arnold and Andrew Lyons report.     

Biogeochemistry of silica in Devils Lake: implications for diatom preservation

Diatom-salinity records from sediment cores have been used to construct climate records of saline-lake basins. In many cases, this has been done without thorough understanding of the preservation potential of the diatoms in the sediments through time. The purpose of this study was to determine the biogeochemistry of silica in Devils Lake and evaluate the potential effects of silica cycling on diatom preservation. During the period of record, 1867–1999, lake levels have fluctuated from 427 m above sea level in 1940 to 441.1 m above sea level in 1999. The biogeochemistry of silica in Devils Lake is dominated by internal cycling. During the early 1990s when lake levels were relatively high, about 94% of the biogenic silica (BSi) produced in Devils Lake was recycled in the water column before burial. About 42% of the BSi that was incorporated in bottom sediments was dissolved and diffused back into the lake, and the remaining 58% was buried. Therefore, the BSi accumulation rate was about 3% of the BSi assimilation rate. Generally, the results obtained from this study are similar to those obtained from studies of the biogeochemistry of silica in large oligotrophic lakes and the open ocean where most of the BSi produced is recycled in surface water. During the mid 1960s when lake levels were relatively low, BSi assimilation and water-column dissolution rates were much higher than when lake levels were high. The BSi assimilation rate was as much as three times higher during low lake levels. Even with the much higher BSi assimilation rate, the BSi accumulation rate was about three times lower because the BSi water-column dissolution rate was more than 99% of the BSi assimilation rate compared to 94% during high lake levels. Variations in the biogeochemistry of silica with lake level have important implications for paleolimnologic studies. Increased BSi water-column dissolution during decreasing lake levels may alter the diatom-salinity record by selectively removing the less resistant diatoms. Also, BSi accumulation may be proportional to the amount of silica input from tributary sources. Therefore, BSi accumulation chronologies from sediment cores may be effective records of tributary inflow.     

Surface influences on the Australian West Coast Trough

Summary  Three dimensional numerical simulations of the Australian West Coast Trough were conducted using a mesoscale model. These simulations represent the process of formation, development and disappearance of the trough and highlight the role of surface features in trough behaviour. Strong land surface heating strengthens the trough whereas topography and sea surface temperatures are of marginal importance. Diurnal variations in surface heating between the land and ocean lead to the trough line oscillating around the coast whereas its more general eastward movement is synoptically controlled. The sea breeze circulation influences local trough orientation through maritime cooling. Received December 23, 1999 Revised November 7, 2000     

Secretinite—reflectance and chemical data from two high volatile bituminous coals (Upper Carboniferous) of North America

Secretinite—a maceral of the inertinite group as recognized by the ICCP in 1996—is a noncellular maceral of seed fern origin. New reflectance data indicate that this maceral has primary anisotropy with bireflectances of 0.4% to 0.9% in high-volatile B bituminous (Ro=0.6%) Carboniferous coal of North America. The highest reflectance is in cross-section as opposed to longitudinal section. Characteristic feature of secretinite is the virtual absence of Si and Al, unlike that in associated vitrinite. This indicates the absence of submicron aluminosilicates in secretinite and their presence in vitrinites. Secretinite is highly aromatic as indicated by low O/C ratios and high contribution of aromatic hydrogen bands detected by FTIR analysis.     

The measurement of reactive silicate in saline-hypersaline lakes: examples of the problem

The analysis of reactive silicate or H₄SiO₄ in saline lake waters using the silicomolybdic acid method developed by Mullin and Riley (1955) suffers from a rather severe salt interference. Our data show that the interference occurs in waters where both chloride and sulfate are the major anions. The interference leads to lower than actual values (by as much as 50 per cent). Until the chemical mechanism of the interference is quantitatively understood, dilution with deionized water appears to be the best approach to obtaining reliable data. This may limit the technique's usage in waters of high TDS, and low reactive silicate.     

Properties, origin and nomenclature of rodlets of the inertinite maceral group in coals of the central Appalachian basin, U.S.A.

Resin rodlets, sclerenchyma strands and woody splinters, which are collectively called rodlets, were studied by chemical, optical petrographic, and scanning-electron microscopic (SEM) techniques. A study was made of such rodlets from the bituminous coal beds of the central Appalachian basin (Pennsylvanian; Upper Carboniferous) of the United States. Comparisons were made with rodlets from coal beds of the Illinois basin, the Southern Anthracite Field of Pennsylvania, the St. Rose coal field of Nova Scotia, and European and other coal fields. In order to determine their physical and chemical properties, a detailed study was made of the rodlets from the Pomeroy coal bed (high volatile A bituminous coal; Monongahela Formation; Upper Pennsylvanian) of Kanawha County, West Virginia. The origin of the rodlets was determined by a comparative analysis of a medullosan (seed fern) stem from the Herrin (No. 6) coal bed (high volatile C bituminous coal; Carbondale Formation) from Washington County, Illinois. Rodlets are commonly concentrated in fusain or carbominerite layers or lenses in bituminous coal beds of the central Appalachian basin. Most of the rodlets examined in our study were probably derived from medullosan seed ferns. The three types of rodlets are distinguished on the basis of cellularity, morphology and fracture.The resin rodlets studied by us are noncellular and appear to be similar in properties and origin to those found in coal beds of the Middle and Upper Pennsylvanian of the Illinois basin. The resin rodlets extracted from the Pomeroy coal bed exhibit high relief and high reflectance when polished and viewed in reflected light; they are opaque in transmitted light. In cross section, the resin rodlets are oval to round and have diameters ranging from 60 to 450 μm. Many are solid, but some have vesicles, canals or cavities, which are commonly filled with clay, probably kaolinite. Typically, they have distinct fracture patterns (“kerfs”) in longitudinal and cross sections and many are characterized by dense (probably oxidized) rims. The orientation and amounts of void space and mineralization of resin rodlets in coal have resulted in much confusion in their recognition and classification. The resin rodlets are petrographically recognized as sclerotinites of the inertinite maceral group. We here propose that resin rodlets be assigned to the maceral variety of sclerotinites termed “resino-sclerotinite” because of their presumable resinous origin. Other investigators have confused some fusinitized resin rodlets with fungal masses, which have different morphological properties and which probably have different chemical properties. We here propose that such fungal masses be assigned to the maceral variety of sclerotinites termed “fungo-sclerotinite.”The sclerenchyma strands examined in our study are cellular, thick-walled, and crescent-shaped in cross section. They exhibit high reflectance and high relief and belong to semifusinite and fusinite of the inertinite maceral group. Sclerenchyma strands are commonly associated with resin canals in Medullosa and related seed-fern genera, which are common in coal balls of the Illinois basin. We here propose adoption of the maceral varietal terms “sclerenchymo-fusinite” and “sclerenchymo-semifusinite” for these bodies.The woody splinters in the Pomeroy coal bed are cellular and thin-walled and have scattered pits as much as a few microns in diameter. They are dark brown to black in transmitted light and commonly have a lower reflectance than the resino-sclerotinite and sclerenchymo-fusinite of the Pomeroy coal. The woody splinters belong to semifusinite and fusinite of the inertinite maceral group. The maceral varietal terms “xylemo-semifusinite” and “xylemo-fusinite” are here proposed for these bodies.Elemental chemical data for the resin rodlets of the Pomeroy coal bed of the central Appalachian basin indicate that resin rodlets have significantly lower atomic H/C and O/C ratios than do sclerenchyma strands and woody splinters. The lower atomic H/C and O/C ratios of the resin rodlets correlate with the highest reflectance. In the coal ball medullosan seed-fern stem from the Herrin (No. 6) coal bed of the Illinois basin, the reflectances of the resin rodlets, woody splinters and sclerenchyma strands are similar and comparable to those of associated vitrinite in the coal ball stem and in the attached coal. However, resin rodlets and sclerenchyma strands in the attached coal have significantly higher reflectances, similar to those of the Pomeroy coal.     

The identification of radial velocity anomalies in the lower mantle using an interference method

A radial velocity anomaly in the lower mantle may cause a triplication in the travel-time curve for short-period P waves, but the first two arrivals may not be separable visually on seismograms over a distance range of about 4–10°. However, the changes of slowness and azimuth as a function of time can be used to infer the presence of interfering signals. Some of the interference effects that can be generated synthetically are often observed on seismograms of earthquakes recorded at the Yellowknife array at distances close to 50°, 80° and 90°. The data from Yellowknife provide evidence for the presence of regions of high velocity gradients at depths of about 1250, 2400 and 2730 km that also show rapid lateral variations. Numerous P arrivals from South American earthquakes that traverse the lowest 500 km of the mantle beneath the Caribbean region have been used to illustrate the main features of the interference method.