Cutaneous soft tissue tumours in dogs: classification, differentiation, and histogenesis

Particular difficulty is regularly encountered in differentiating on routine morphological grounds between soft tissue tumours in dogs, especially fibrosarcoma, including myxosarcoma; haemangiopericytoma; and schwannoma. In this study we report the findings of the immunohistochemical examination of 74 canine tumours classified as soft tissue tumours by routine light microscopy. As a consequence, we propose that the morphologic diagnosis of cutaneous fibrosarcoma, haemangiopericytoma or schwannoma carries little precision in respect of tumour cell differentiation, and would support use of the term 'spindle cell tumour of canine soft tissue' to encompass this group of lesions.     

Plasticity in vertical behaviour of migrating juvenile southern bluefin tuna (Thunnus maccoyii) in relation to oceanography of the south Indian Ocean

Electronic tagging provides unprecedented information on the habitat use and behaviour of highly migratory marine predators, but few analyses have developed quantitative links between animal behaviour and their oceanographic context. In this paper we use archival tag data from juvenile southern bluefin tuna ( Thunnus maccoyii , SBT) to (i) develop a novel approach characterising the oceanographic habitats used throughout an annual migration cycle on the basis of water column structure (i.e., temperature-at-depth data from tags), and (ii) model how the vertical behaviour of SBT altered in relation to habitat type and other factors. Using this approach, we identified eight habitat types occupied by juvenile SBT between the southern margin of the subtropical gyre and the northern edge of the Subantarctic Front in the south Indian Ocean. Although a high degree of variability was evident both within and between fish, mixed-effect models identified consistent behavioural responses to habitat, lunar phase, migration status and diel period. Our results indicate SBT do not act to maintain preferred depth or temperature ranges, but rather show highly plastic behaviours in response to changes in their environment. This plasticity is discussed in terms of the potential proximate causes (physiological, ecological) and with reference to the challenges posed for habitat-based standardisation of fishery data used in stock assessments.     

杂交改良对撒坝猪肌肉品质的影响——肌肉化学成分分析

 选用24kg左右的去势撒坝猪及其约长撒三元杂交猪各7头，根据基因型分成2组, 按活重变化分为3个试验期 （前期20～35kg，中期35～60kg和后期60～90kg），在同一试验期内饲喂同样的日粮进行饲养试验，当活重达90kg进行屠宰试验，研究杂交改良对云南省本地猪种撒坝猪肌肉化学成分的影响。撒坝猪通过杂交改良后，生长速度和瘦肉率显著提高，但其肉品质均有不同程度的下降。杂交后代鲜肉的总氨基酸含量有降低的趋势，但统计学差异不显著（P＞0.05）；撒坝猪鲜肉的赖氨酸含量显著地比杂交猪的高（P＜0.05），在干肉样中，二者的差异不显著（P＞0.05）；然而，撒坝猪的组氨酸含量在鲜样和干样中都显著地比杂交猪的高（P＜0.01）。肌肉中脂肪酸的测定结果显示，撒坝猪肌肉中的油酸（C_18∶1）和亚麻酸（C_18∶3）的含量显著地比杂交猪的高（P＜0.05）；尽管统计学的差异不显著，撒坝猪肌肉中的豆酸蔻（C_14∶1）, 和棕榈油酸（C_16∶1）显示了比杂交猪的高趋势（P＞0.05）；然而，杂交猪肌肉中亚油酸 （C_18∶2）的含量显著地比撒坝猪中的高（P＜0.05）；两个组的棕榈酸（C_16∶0），硬脂酸（C_18∶0） 和花生酸（C_20∶0）含量相同（P＞0.05）。     

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.     

Incorporation of Fresh and Cryopreserved Bone in Osteochondral Autografts in the Horse

The structural integrity of subchondral bone in fresh and frozen osteochondral autografts was investigated at month 3 in 10 horses. Two osteochondral autografts were harvested from the lateral aspect of the lateral trochlear ridge of the left talus in each of 10 anesthetized horses. Grafts were frozen in 7.5% DMSO. After 14 days, the thawed grafts were press-fitted into drill holes in the trochlear ridges of the right stifles. A fresh graft from the right hock was implanted in each left stifle. To control for the effects of surgery, a fresh graft was transferred from the right stifle to the left stifle. The end result was two grafts in each femoropatellar joint. Fresh and frozen bone grafts maintained a structurally intact support for the cartilage surface. Graft stability and surface congruency were determining factors in the outcome of the grafts. Incorporation of both types of graft was complete at month 3, but remodeling of the fresh grafts was more active.     

RADIOGRAPHICALLY VISUALIZED SKELETAL CHANGES ASSOCIATED WITH MUCOPOLYSACCHARIDOSIS VI IN CATS

The radiographic skeletal form and structure of all cats with mucopolysaccharidosis VI is described. Common manifestations included epiphyseal dysplasia, generalized osteoporosis, abnormal nasal turbinate development, his subluxation, impaired development of skeletal growth, pectus excavatum, hyoid hypoplasia, aplasia, hypoplasia and fragmentation or abnormal ossification of the dens, and aplasia or hypoplasia of frontal and sphenoid sinuses. The skeletal measurements of two affected cats were compared with those of normal, sex-matched littermates, and the measurements of two affected female cats were compared with those of a normal male littermate.     

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.