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1.
One hundred and twenty-four patients over the age of 75 years were assessed for the cause of their macrocytosis (MCV > 95 fl). A definitive diagnosis was reached in 75/124 (60%) by non-invasive techniques. The remainder underwent a bone marrow biopsy yielding a definitive diagnosis in a further six patients who had an identifiable myelodysplastic syndrome (MDS). A high proportion of the remainder had morphological abnormalities which fitted with no recognized pathological entity. It is suggested that these may represent MDS in evolution.  相似文献   
2.
Nutrient export from agricultural land to surface waters is a significant environmental concern within the Great Lakes Basin (GLB). A field-based watershed-scale study was completed to investigate spatial and temporal variations of phosphorus and nitrate to assess nutrient transport pathways and groundwater-surface water interactions in an agriculturally dominated clay plain system. This was conducted in the 127 km2 Upper Parkhill Watershed, near Lake Huron in southwestern Ontario, Canada. Data collection occurred from June 2018 to May 2019 via continuous sensor deployment and discrete sampling of stream water, groundwater, hyporheic zone, and tile drainage water. Samples were analyzed for various nutrient species (total, total dissolved, soluble reactive, and particulate phosphorus, and nitrate-N) to examine the hydrological dynamics of principal transport pathways of agriculturally-derived nutrients. Total phosphorus and nitrate concentrations in stream water ranged from 0.007 to 0.324 mg/L and 0.32 to 13.13 mg NO3?-N/L, respectively. Tile drainage water total phosphorous concentrations varied from 0.006 to 0.066 mg/L. Groundwater total dissolved phosphorus concentrations ranged from <0.003 to 0.085 mg/L. Transport of phosphorus through tile drainage was observed to be greater than through groundwater over the study period. No distinct relationship was observed between nutrient concentrations in the hyporheic zone and the vertical hydraulic gradient within this zone in the studied stream reach. Preliminary correlations were discerned between water quality observations and recognized land management practices. Given the elevated stream nutrient concentrations, these results are consequential for the continual improvement of strategies and programs devised to conserve water resources within the GLB.  相似文献   
3.
Northern Grey and Bruce counties are situated centrally in the Lake Huron basin of the Great Lakes area of North America and are similarly central to the area of glacial Lake Algonquin, the largest glacial lake of the Great Lakes area. Ten survey traverses at sites in northern Grey and Bruce counties have documented the continuation of Lake Algonquin and Nipissing phase shorelines onto the Bruce Peninsula from previous work to the east. The Algonquin shoreline near 240 m ASL (above sea level) rises northward above land high enough to record it near Lion's Head. The Nipissing shoreline at 191 m ASL defines a shallow strait across the Bruce Peninsula near Ferndale, which was flooded temporarily at the maximum of the Nipissing transgression, separating northern Bruce Peninsula from the mainland. Uplift and Port Huron outlet downcutting later rejoined the island to the mainland as it is today. Raised beaches define Algonquin and Nipissing regressions by uplift using the Port Huron outlet. Paleobiotic records in a sand dune at Oliphant (molluscs), a Nipissing shorebluff along Sucker Creek (molluscs) and several sites in the former Nipissing shallow water strait near Ferndale (molluscs, ostracodes, plant macrofossils), provide paleoenvironmental data and supplement prior pollen studies at Lake Charles, Slough of Despond, and Hope Bay. Lake Algonquin deep water rhythmite clays are barren of fossils, whereas Nipissing shallow water silts are fossiliferous.  相似文献   
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4 结果和讨论 4.1 焊盘间的桥接 结果比较表明,使用不同的治具配置有明显的区别.使用平台治具作为板支撑的激光切割钢网在80 μm间隙的情况下未发现桥接.使用真空支撑时,激光切割钢网在50 μm间隙的情况下也未发现桥接.这说明使用真空支撑在印刷时的钢网和电路板间间隙更小,支撑性能更好.图5显示了其在125 μm×15...  相似文献   
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This paper proposes the use of design patterns to capture best practices in object-oriented finite element programming. Five basic design patterns are presented. In Model-Analysis separation, analysis-related classes are separated from those related to finite element modelling. Model-UI separation separates responsibilities related to the user interface from model classes. Modular Element uses object composition to reduce duplication in element type classes while avoiding the problems associated with class inheritance. Composite Element lets clients handle substructures and elements uniformly. Decomposing the analysis subsystem as in Modular Analyzer increases reuse and flexibility. Alternative solutions to each pattern are also reviewed.  相似文献   
8.
Interaction nets were introduced almost 15 years ago. Since then they have been put forward as both a graphical programming paradigm and as an intermediate language into which we can compile other languages. Whichever way we use interaction nets, a problem remains in that the language is very primitive. Drawing an analogy with functional programming, we have the λ-calculus but we are missing the functional programming language: syntactic sugar, language constructs, data-structures, etc. The purpose of this paper is to make a first step towards defining such a programming language for interaction nets.  相似文献   
9.
The ρ-calculus generalises both term rewriting and the λ-calculus in a uniform framework. Interaction nets are a form of graph rewriting which proved most successful in understanding the dynamics of the λ-calculus, the prime example being the implementation of optimal β-reduction. It is thus natural to study interaction net encodings of the ρ-calculus as a first step towards the definition of efficient reduction strategies. We give two interaction net encodings which bring a new understanding to the operational semantics of the ρ-calculus; however, these encodings have some drawbacks and to overcome them we introduce bigraphical nets—a new paradigm of computation inspired by Lafont's interactions nets and Milner's bigraphs.  相似文献   
10.
The purpose of this paper is to demonstrate how Lafont's interaction combinators, a system of three symbols and six interaction rules, can be used to encode linear logic. Specifically, we give a translation of the multiplicative, exponential, and additive fragments of linear logic together with a strategy for cut-elimination which can be faithfully simulated. Finally, we show briefly how this encoding can be used for evaluating λ-terms. In addition to offering a very simple, perhaps the simplest, system of rewriting for linear logic and the λ-calculus, the interaction net implementation that we present has been shown by experimental testing to offer a good level of sharing in terms of the number of cut-elimination steps (resp. β-reduction steps). In particular it performs better than all extant finite systems of interaction nets.  相似文献   
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