SUCROSE: PRECISE DETERMINATION OF CRYSTAL AND MOLECULAR STRUCTURE BY NEUTRON DIFFRACTION

This analysis provides the first precise molecular parameters for sucrose. All hydrogen atoms are included. Carbon-carbon distances are 1.51 1.53 A; carbon-oxygen 1.40 to 1.44 A; carbon-hydrogen 1.08 to 1.11 A; oxygen-hydrogen 0.94 to 0.99 A. The furanose ring conformation differs from that in sucrose sodium bromide dihydrate. Hydrogen bonds (two of them intramolecular) utilize every hydroxyl group except one.     

The Demise of Distance? The Declining Role of Physical Proximity for Knowledge Transmission

ABSTRACT The transmission of knowledge diminishes with physical distance, one factor explaining the geographic clustering of scientific and industrial activity. The authors investigate how those distances have stretched over time—between collaborating inventors, and between inventors and the technology that inspires them. While physical distance is still a factor, it is clear that its constraining effects have weakened, especially for particular types of innovators, technologies, and regions of the United States.     

Heritility of field resistance to potato leafroU virus in cultivated potato

Potato progenies in a line x tester mating design and the clonal parents were screened for field resistance to potato leafroll virus (PLRV) to determine the heritability of this trait. Twelve advanced potato clones or varieties were crossed as pistillate parents to two pollen testers. The seedling progenies and clonal parents were exposed to aphid-transmitted potato leafroll virus for two growing seasons. Cumulative infection by potato leafroll virus was determined by post-season sero-logical indexing of foliage grown from sprouted tubers after 2 years of exposure. Narrow-sense heritability was estimated from regression of mid-parent on progeny as h = 0.72. This estimate indicates a high level of useabie genetic variance for PLRV resistance in advanced breeding materials. Although variation in resistance to PLRV appears to be a quantitative trait in susceptible and moderately resistant clones, per-formance of the most resistant parents suggests that genes with major effects may be present. These results are similar to the conclusions of other researchers who found one or two genes controlling the pheno-types of extreme resistance, resistance to infection, or suppression of virus titre.     

Continuity and Change in an Old Industrial Region

Analysts have debated the extent to which recent economic changes represent a continuation of earlier patterns or a fundamental shift to a new industrial order. We trace and extend the spatial implications of this debate for a mature industrial region, the Ohio River Valley, part of the American Manufacturing Belt, for the 1980-90 period. The paper builds on recent research arguing that such regions had a diverse, rather than homogeneous, space-economy. Empirical findings clearly demonstrate diversity of economic structures, sectorally and spatially, emphasizing both continuity and change in an old industrial region, and the totality of economic activity rather than specific sectors identified with the rise or transformation of industrial capitalism. In terms of change, aggregate trends follow national ones, but do not wash evenly over the Ohio River Valley. Nor do they mirror, when considered at a sub-regional scale, patterns indicated by de-industrialization and post-Fordist transition frameworks. Findings provide implications for elaborating or augmenting these perspectives, and types of research needed to accomplish the task.     

Canadian Investment in Northern New York: Impact of Exchange Rates on Foreign Direct Investment

This paper investigates the determinants of Canadian direct investment in Northern New York, focusing on the influence of changing foreign exchange rates. Hypotheses are formulated that new investment should be positively related to the value of the U.S. dollar while expansions of existing facilities ought to be unrelated to exchange rate movements. These predictions are supported by the data. Since Canadian investment is found to behave quite differently from domestic-source investment, we conclude that other factors besides exchange rates account for much of this difference.¹     

Extending Carlino-Mills Models to Examine Urban Size and Growth Impacts on Proximate Rural Areas

ABSTRACT A modification of the Boamet model of local economic change is developed that links the growth of urban nodes in functional economic regions to employment and population change in the rural hinterlands of these regions. The two-equation model uses labor market and residential zone observations that are consistent with commuter fields around each rural community in the regions studied. The model parameters are estimated for 204 Danish rural municipalities, for 3515 rural communes in six regions of Eastern France, and for 268 rural census tracts in South Carolina. Results indicate that urban nodal spread effects are often significant and tend to dominate urban backwash impacts on rural communities. Accordingly, rural communities need to be concerned with the economic fortunes of their urban nodes and with policies that affect the pattern of urban growth between urban center and the urban fringe.     

Do Entrepreneurs Enhance Economic Growth in Lagging Regions?

Because support for entrepreneurship is often a core part of economic development strategies, we investigate whether it is important for growth in lagging, rural U.S. regions by focusing on Appalachia. While entrepreneurship has the advantage of being endogenous and “home grown,” previous research suggests that remote rural regions may lack the agglomeration economies to benefit greatly from entrepreneurship. Using county‐level data, we explore the relationship between entrepreneurship and economic growth, employing self‐employment and small business data as proxies for entrepreneurship. We look at the results for the Appalachian Regional Commission (ARC) region, using its immediate Appalachian neighbors outside the ARC region as a control group. Moreover, we also account for self‐sorting by proprietors to locate in expanding regions. Despite strong barriers to growth in Appalachia, our empirical results suggest that self‐employment is positively associated with employment and income growth, and that efforts to promote entrepreneurial capacity may be among the few economic development strategies with positive payoffs in remote regions.     

Multiple squamous cell carcinoma of the digits in two cats

This paper describes the clinical and pathological features of two cats with squamous cell carcinoma affecting several digits. Similar lesions have been described in dogs and humans.     

In Vitro Biomechanical Comparison of Solid and Tubular Interlocking Nails in Neonatal Bovine Femurs

This study biomechanically evaluates solid and tubular interlocking nails in bovine neonatal femurs. Paired femurs from 40 neonatal dairy calves were obtained for mechanical testing. Intact femurs and four combinations of experimentally manipulated femurs (intact or ostectomized femurs with either a solid or tubular interlocking nail) were tested in craniocaudal and lateromedial bending, eccentric axial compression, and external torsion to evaluate composite rigidity, local/gap stiffness, and load to failure (compression and torsion only). In torsional composite rigidity, femurs with tubular interlocking nails were more compliant than intact femurs or intact femurs with solid interlocking nails (P <.001). Ostectomized femurs with solid interlocking nails were similar to intact femurs with tubular interlocking nails. Within femurs with tubular interlocking nails, ostectomized femurs were more compliant than intact femurs (P <.0001). In craniocaudal and lateromedial bending rigidity, ostectomized femurs were more compliant than intact femurs, regardless of interlocking nail type (P <.001). Within ostectomized femurs, tubular interlocking nails were more compliant than solid interlocking nails in craniocaudal bending (P <.05) and there was a similar trend in lateromedial bending (P=.06). In eccentric axial compression, local/ gap stiffness was significantly greater in intact femurs compared with intact femurs with solid (48% of intact bone) or tubular (45% of intact bone) interlocking nails and ostectomized femurs with solid (18% of intact bone) or tubular (11 % of intact bone) interlocking nails (P <.0001). In torsional testing, local/gap stiffness was not significantly different between intact femurs and intact femurs with interlocking nails, but was significantly lower in ostectomized femurs with solid (2% of intact bone) and tubular (0.2% of intact bone) interlocking nails (P <.0001). In torsional and compressive failure testing, plastic deformation of the tubular interlocking nail occurred at the unoccupied screw hole at the ostectomy site before bone failure. Interlocking nails should be considered as an optional repair method for neonatal bovine femoral fractures. Until the actual physiological loading characteristics of neonatal calf femurs are measured, it is uncertain whether solid or tubular interlocking nails tested in this study will provide sufficient strength and stiffness to stabilize neonatal bovine femoral fractures and facilitate healing.