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The larch casebearer [Coleophora laricella (Hubner)], a non-native insect, continues to impact western larch (Larix occidentalis Nutt.) through defoliation events in the Pacific Northwest. Biological control programs starting in the 1960s released seven species of parasitoid wasps to control C. laricella outbreaks. However, information about current population dynamics of C. laricella and associated parasitoids remains lacking. Therefore, the goal of this study was to document the presence, current distributions, densities, and parasitism rates of introduced and native parasitoid wasps occurring on C. laricella throughout the Northwestern U.S. range of L. occidentalis. We sampled L. occidentalis trees at multiple sites in Oregon, Washington, Idaho, and Montana. C. laricella was present at all sites with average state densities ranging from 6.2 to 13.1 moths/100 buds. We recovered two introduced hymenopteran biological control agents; Agathis pumila (Ratzeburg: Braconidae) at 79% of the sites, and Chrysocharis laricinellae (Ratzeburg: Eulophidae) at 63% of the sites. Fourteen species of native parasitic wasps were also recovered. The most common species were: Bracon sp., Spilochalcis albifrons, and Mesopolobus sp. The average native species parasitism rate across the four states was 9.0%, which was higher than the introduced species Ch. laricinellae (2.9%), but not as high as A. pumila (19.3%). While survey results suggest that native species may be more important for the control of C. laricella than previously thought, A. pumila remains the major source of regional control. However, further research is needed to better understand how introduced and native parasitoids interact to control invasive pest populations.

Old conifer forests in the Pacific Northwest have a wide range of microhabitats induced by canopy structure and substrate characteristics. We used the Wind River Canopy Crane to sample lichens and bryophytes throughout the spectrum of habitats available to epiphytes. Of the 111 species found in 72 sample units, 97 were lichens and 14 were bryophytes. Epiphyte communities showed marked variation with respect to height in the canopy, bark vs. wood, degree of sheltering, and stem diameter. Of these factors, height in the canopy was most strongly related to epiphyte communities. Furthermore, the top two meters of the tallest trees hosted a diverse assemblage of both rare species (Tholurna dissimilis) and weedy, nitrophilous species (Candelaria concolor, Hypogymnia tubulosa, Parmelia sulcata), presumably induced by birds delivering lichen propagules and nutrients. Ten species were more frequent on bare wood than bark, including Ophioparma rubricosa, Letharia vulpina, Placynthiella spp., Ptychographa x...

Theoretical and empirical methods were applied to the analysis of branch growth and crown form in old trees of coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii). Conventional use of allometric models proved insufficient in explaining the variability found in the relationship between branch diameter and length. In order to infer the potential pattern of branch growth, a maximum relationship was empirically estimated by selecting maximum points in an incremental fashion. This relationship asymptoted to infinity, suggesting that factors such as damage and die-back may modify the branch diameter–length relationship before an asymptotic maximum length is reached. The difference between the observed branch length and the estimated maximum branch length was found to be a good measure of the degree of branch damage. The degree of damage increased with increasing branch diameter, suggesting that large diameter branches have experienced more extensive damage and/or die-back. This trend was stronger in dead branches than in live branches. A conceptual model of branch growth is proposed where damage and die-back modify the branch diameter–length relationship, severe damage and die-back lead to branch death, and recovery helps to restore the relationship in live branches. The vertical distribution of branch diameters within the crown was analyzed to characterize crown form. An allometric model describing the maximum relationship between branch height and branch diameter was fit to each tree. Two types of distribution patterns were identified: the conical and rounded. The frequency distributions of branch diameters at three crown levels (upper, mid and lower crown) were also used to characterize crown form. Three crown types were characterized: the mature crown, old crown, and stressed crown. These crown types corresponded well with the vertical distribution patterns of maximum branch diameters. The two criteria are suggested as a useful tool for characterizing crown form in old coastal Douglas-fir for purposes of forest management.

A detailed analysis of diameter-height relationships was applied to an old-growth Pseudotsuga menziesii (Mirb.) Franco var. menziesii - Tsuga heterophylla (Raf.) Sarg. forest in southwestern Washington State, U.S.A., to predict future development of vertical stratification among tree species. Differences among species in relative abundance and size structure resulted in diameter-height regressions of varying certainty and stability. Damage and shading had negative impacts on predicted heights and estimates of maximum attainable height (Hmax) in all species. However, species varied as to the main causes and size dependency of damage in relation to tree height. Current height-growth rates of the upper canopy species declined with increasing tree height, reaching minimum values near the predicted Hmax. The future development of the forest canopy would involve a slow invasion of the upper canopy by Tsuga heterophylla and Thuja plicata Donn ex D. Don, as P. menziesii are near their maximum attainable height, and Abies amabilis Dougl. ex Forbes and Taxus brevifolia Nutt. are restricted to the middle to lower canopy. However, if current height-growth rates continue, P. menziesii should maintain its dominant status in the upper canopy for at least another century.

A detailed analysis of diameter-height relationships was applied to an old-growth Pseudotsuga menziesii (Mirb.) Franco var. menziesii - Tsuga heterophylla (Raf.) Sarg. forest in southwestern Washington State, U.S.A., to pre- dict future development of vertical stratification among tree species. Differences among species in relative abundance and size structure resulted in diameter-height regressions of varying certainty and stability. Damage and shading had negative impacts on predicted heights and estimates of maximum attainable height (Hmax) in all species. However, spe- cies varied as to the main causes and size dependency of damage in relation to tree height. Current height-growth rates of the upper canopy species declined with increasing tree height, reaching minimum values near the predicted Hmax. The future development of the forest canopy would involve a slow invasion of the upper canopy by Tsuga heterophylla and Thuja plicata Donn ex D. Don, as P. menziesii are near their maximum attainable height, and Abies amabilis Dougl. ex Forbes and Taxus brevifolia Nutt. are restricted to the middle to lower canopy. However, if current height- growth rates continue, P. menziesii should maintain its dominant status in the upper canopy for at least another century.

The accuracy of ground based estimates using the six-class dwarf mistletoe rating system was evaluated in an old-growth Douglas-fir/western hemlock forest by comparing ground ratings by five different observers to an examination of tree crowns from a construction crane at the Wind River Canopy Crane Research Facility, Washington. A total of 139 dominant, codominant, and intermediate western hemlock were evaluated. No consistent pattern emerged to indicate where overall error was made. All but one observer was relatively accurate at identifying noninfected trees (73 to 95% noninfected trees accurately rated by four observers). However, the observers were less accurate at estimating the DMR class of the infected trees (11% to 3 7% of the infected trees accurately rated), including a number of trees incorrectly rated by two or more DMR classes. One observer rated 98% of the trees as having infections, while the crane survey estimated only 53% of the trees as having infections. Each observer divided the individual tree crowns into thirds and estimated infections based on summing lower, middle, and upper canopy levels. There was no pattern to the errors associated with estimates by canopy level. One observer significantly overestimated all canopy levels, one observer estimated all accurately, one observer significantly underestimated all canopy levels, one observer underestimated the mid and upper canopies, and one observer underestimated the lower and upper canopies. The principal reasons for inaccurate dwarf mistletoe ratings were assumed to be difficulty in accurately estimating crown thirds, misidentification of infections because of various stem deformities or accumulation of organic debris resembling infections, and the difficulty in observing infections high above the ground and through dense vegetation. Only one of the five observers accurately represented the spatial pattern of the infection center. The implications of this research vary depending on whether the results are to be used for timber management or for research and modeling applications. West. J. Appl. For. 15(1):8-14.

Epiphyte functional groups (alectorioid lichens, cyanolichens, other lichens, and bryophytes) were sampled in nine old-growth, canopy-emergent, Pseudotsuga menziesii trees along a riparian corridor...

Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible reference species (western hemlock, Tsuga heterophylla) to evaluate their use as proxies for variation in past SNC infection, particularly in relation to potential explanatory climate factors. We sampled trees from an Oregon site where a fungicide trial took place from 1996 to 2000, which enabled the comparison of stable isotope values between trees with and without disease. Carbon stable isotope discrimination (Δ(13)C) of treated Douglas-fir tree-rings was greater than that of untreated Douglas-fir tree-rings during the fungicide treatment period. Both annual growth and tree-ring Δ(13)C increased with treatment such that treated Douglas-fir had values similar to co-occurring western hemlock during the treatment period. There was no difference in the tree-ring oxygen stable isotope ratio between treated and untreated Douglas-fir. Tree-ring Δ(13)C of diseased Douglas-fir was negatively correlated with relative humidity during the two previous summers, consistent with increased leaf colonization by SNC under high humidity conditions that leads to greater disease severity in following years.

The occurrence and pattern of stains in the base and lower stem of young-growth western hemlock (Tsugaheterophylla (Raf.) Sarg.) and its relationship to root disease were studied at 16 sites in coastal Washington. Stands ranged in age from 17 to 35 years and were precommercially thinned 5–17 years previously. The most common stain was discolored wood or wetwood, which is a type of heartwood in standing trees that has been internally infused with water. Wetwood occurred in more than 50% of the 1215 trees examined, and within some stands it occurred in 80% of the trees examined. The presence of wetwood did not indicate root disease or other decay. However, all wood decay infections were associated with wetwood. Wetwood can be economically important because it interferes with drying and causes shake and warping in lumber. Incipient decay stain was less common (

The cytochrome P450 superfamily of enzymes play a central part in the metabolism of carcinogens and anti-cancer drugs. The expression, cellular localisation, and distribution of different forms of P450 and the functionally associated enzymes epoxide hydrolase and glutathione S-transferases have been investigated in oesophageal cancer and non-neoplastic oesophageal tissue using immunohistochemistry. Expression of the different enzymes was confined to epithelial cells in both non-neoplastic samples and tumour samples except the CYP3A was also identified in mast cells and glutathione S-transferase pi was present in chronic inflammatory cells. CYP1A was present in a small percentage of non-neoplastic samples but both CYP2C and CYP3A were absent. Epoxide hydrolase was present in half of the non-neoplastic samples and the different classes of glutathione S-transferase were present in a low number of samples. In carcinomas CYP1A, CYP3A, epoxide hydrolase, and glutathione S-transferase pi were expressed in at least 60% of samples. The expression of glutathione S-transferases alpha and mu were significantly less in adenocarcinoma compared with squamous carcinoma.

Time-dependent charge buildup and annealing processes cause the ionizing radiation response of CMOS devices and circuits to depend strongly on the dose rate of the exposure. Oxide-trap charge annealing and interface-trap buildup in nMOS transistor can lead to positive threshold voltage shifts in a space environment, while negative threshold voltage shifts are commonly observed after irradiations at typical laboratory dose rates [50–300 rad(Si)/s]. Thus, devices that pass laboratory testing can fail at the low dose rates encountered in space due to positive nMOS transistor threshold-voltage shifts above preirradiation values, i.e. “rebound”. We summarize how this issue can be addressed in total-dose hardness assurance test methods for space. An example of such a guideline is the revised U.S. military-standard ionizing-radiation-effects test method (MIL-STD 883D, Test Method 1019.4).

Although there is acute concern that insect-caused tree mortality increases the likelihood or severity of subsequent wildfire, previous studies have been mixed, with findings typically based on stand-scale simulations or individual events. This study investigates landscape- and regional-scale wildfire likelihood following outbreaks of the two most prevalent native insect pests in the US Pacific Northwest (PNW): mountain pine beetle (MPB; Dendroctonus ponderosae) and western spruce budworm (WSB; Choristoneura freemani). We leverage seamless census data across numerous insect and fire events to (1) summarize the interannual dynamics of insects (1970–2012) and wildfires (1984–2012) across forested ecoregions of the PNW; (2) identify potential linked disturbance interactions with an empirical wildfire likelihood index; (3) quantify this insect-fire likelihood across different insect agents, time lags, ecoregions, and fire sizes. All three disturbance agents have occurred primarily in the drier, interior conif...

Halliburton has been directing a multi-year, cross-industry initiative to develop a web-based Information Resource for Water Management Technology. It aims to help the working engineer to understand current and up-to-date Water Management principles, technologies, best practices and lessons learned. We present the philosophy and methodology employed in the analysis, design and implementation of this important industry resource.

This paper seeks to identify what developments and technological advances can be made to the existing railway maintenance regime by the application of intelligent condition monitoring systems. This paper has been specifically tailored to focus on the railway industry, in particular the signalling infrastructure.

Ground-based measurements of stores, growth, mortality, litterfall, respiration, and decomposition were conducted in an old-growth forest at Wind River Experimental Forest, Washington, USA. These measurements were used to estimate gross primary production (GPP) and net primary production (NPP); autotrophic respiration (Ra) and heterotrophic (Rh) respiration; and net ecosystem production (NEP). Monte Carlo methods were used to calculate uncertainty (expressed as ± 2 standard deviations of 200–400 calculations). Live carbon (C) stores were 39,800 g C m )2 (34,800– 44,800 g C m )2 ). The store of C in detritus and mineral soil was 22,092 g C m )2 (20,600–23,600 g Cm )2 ), and the total C stores were 61,899 g C m )2 (56,600–67,700 g C m )2 ). Total NPP was 597 g C m )2 y )1 (453 to 741 g C m )2 y )1 ). Ra was 1309 g C m )2 y )1 (845–1773 g C m )2 y )1 ), indicating a GPP of 1906 g C m )2 y )1 (1444–2368 g C

We describe the three-dimensional structure of an old-growth Douglas-fir/western hemlock forest in the central Cascades of southern Washington, USA. We concentrate on the vertical distribution of foliage, crowns, external surface area, wood biomass, and several components of canopy volume. In addition, we estimate the spatial variation of some aspects of structure, including the topography of the outer surface, and of microclimate, including the within-canopy transmittance of photosynthetically active radiation (PAR). The crowns of large stems, especially of Douglas-fir, dominate the structure and many aspects of spatial variation. The mean vertical profile of canopy surfaces, estimated by five methods, generally showed a single maximum in the lower to middle third of the canopy, although the height of that maximum varied by method. The stand leaf area index was around 9 m2 m−2, but also varied according to method (from 6.3 to 12.3). Because of the deep narrow crowns and numerous gaps, the outer canopy surface is extremely complex, with a surface area more than 12 times that of the ground below. The large volume included below the outer canopy surface is very porous, with spaces of several qualitatively distinct environments. Our measurements are consistent with emerging concepts about the structure of old-growth forests, where a high degree of complexity is generated by diverse structural features. These structural characteristics have implications for various ecosystem functions. The height and large volume of the stand indicate a large storage component for microclimatic variables. The high biomass influences the dynamics of those variables, retarding rates of change. The complexity of the canopy outer surface influences radiation balance, particularly in reducing short-wave reflectance. The bottom-heaviness of the foliage profile indicates much radiation absorption and gas exchange activity in the lower canopy. The high porosity contributes to flat gradients of most microclimate variables. Most stand respiration occurs within the canopy and is distributed over a broad vertical range.

The Wind River old-growth forest, in the southern Cascade Range of Washington State, is a cool (average annual temperature, 8.7°C), moist (average annual precipitation, 2223 mm), 500-year-old Douglas-fir–western hemlock forest of moderate to low productivity at 371-m elevation on a less than 10% slope. There is a seasonal snowpack (November–March), and rain-on-snow and freezing-rain events are common in winter. Local geology is characterized by volcanic rocks and deposits of Micocene/Oligocene Micocene-Oligocene (mixed) Micocene and Quaternary age, as well as intrusive rocks of Miocene age. Soils are medial, mesic, Entic Vitrands that are deep (2–3 m), well drained, loams and silt loams, generally stone free, and derived from volcanic tephra. The vegetation is transitional, between the Western Hemlock Zone and the Pacific Silver Fir Zone, and the understory is dominated by vine maple, salal, and Oregon grape. Stand structural parameters have been measured on a 4-ha plot. There are eight species of conifers, with a stand density of 427 trees ha−1 and basal area of 82.9 m2 ha−1. Dominant conifers include Douglas-fir (35 trees ha−1), western hemlock (224 trees ha−1), Pacific yew (86 trees ha−1), western red cedar (30 trees ha−1), and Pacific silver fir (47 trees ha−1). The average height of Douglas-fir is 52.0 m (tallest tree, 64.6 m), whereas western hemlock averages 19.0 m (tallest tree, 55.7 m). The regional disturbance regime is dominated by high-severity to moderate-severity fire, from which this forest is thought to have originated. There is no evidence that fire has occurred in the forest after establishment. Primary agents of stand disturbance, which act at the individual to small groups of trees scale, are wind, snow loads, and drought, in combination and interacting with root-rot and butt-rot fungi, heart-rot fungi, dwarf mistletoe, and bark beetles. The forest composition is slowly shifting from dominance by Douglas-fir, a shade-intolerant species, to western hemlock, western red cedar, Pacific yew, and Pacific silver fir, all shade-tolerant species. The Wind River old-growth forest fits the regional definition of Douglas-fir “old growth” on western hemlock sites.

Lodgepole pine (Pinus contorta) forests are widely distributed throughout North America and are subject to mountain pine beetle (Dendroctonus ponderosae) epidemics, which have caused mortality over millions of hectares of mature trees in recent decades. Mountain pine beetle is known to influence stand structure, and has the ability to impact many forest processes. Dwarf mistletoe (Arceuthobium americanum) also influences stand structure and occurs frequently in post-mountain pine beetle epidemic lodgepole pine forests. Few studies have incorporated both disturbances simultaneously although they co-occur frequently on the landscape. The aim of this study is to investigate the stand structure of lodgepole pine forests 21-28 years after a mountain pine beetle epidemic with varying levels of dwarf mistletoe infection in the Deschutes National Forest in central Oregon. We compared stand density, stand basal area, canopy volume, proportion of the stand in dominant/codominant, intermediate, and suppressed cohorts, average height and average diameter of each cohort, across the range of dwarf mistletoe ratings to address differences in stand structure. We found strong evidence of a decrease in canopy volume, suppressed cohort height, and dominant/codominant cohort diameter with increasing stand-level dwarf mistletoe rating. There was strong evidence that as dwarf mistletoe rating increases, proportion of the stand in the dominant/codominant cohort decreases while proportion of the stand in the suppressed cohort increases. Structural differences associated with variable dwarf mistletoe severity create heterogeneity in this forest type and may have a significant influence on stand productivity and the resistance and resilience of these stands to future biotic and abiotic disturbances. Our findings show that it is imperative to incorporate dwarf mistletoe when studying stand productivity and ecosystem recovery processes in lodgepole pine forests because of its potential to influence stand structure.

Logistic regression models used to predict tree mortality are critical to post-fire management, planning prescribed burns and understanding disturbance ecology. We review literature concerning post-fire mortality prediction using logistic regression models for coniferous tree species in the western USA. We include synthesis and review of: methods to develop, evaluate and interpret logistic regression models; explanatory variables in logistic regression models; factors influencing scope of inference and model limitations; model validation; and management applications. Logistic regression is currently the most widely used and available technique for predicting post-fire tree mortality. Over 100 logistic regression models have been developed to predict post-fire tree mortality for 19 coniferous species following wild and prescribed fires. The most widely used explanatory variables in post-fire tree mortality logistic regression models have been measurements of crown (e.g. crown scorch) and stem (e.g. bole char) injury. Prediction of post-fire tree mortality improves when crown and stem variables are used collectively. Logistic regression models that predict post-fire tree mortality are the basis of simple field tools and contribute to larger fire-effects models. Future post-fire tree mortality prediction models should include consistent definition of model variables, model validation and direct incorporation of physiological responses that link to process modelling efforts.

Techniques to monitor growth and mortality of live trees, and longevity of snags were developed and tested on 8 units in the Oregon and Washington Cascades where new forestry (structural retention) cuttings were utilized. Time and costs were quantified. The total area of three aggregated units and five dispersed units was 27.8 ha, with 2407 trees and snags measured on 25.1 ha of sample area. Cost of field work was approximately $4590 (4 person crew at 6 weeks) while costs of data entry, analysis and report writing were approximately $2000 (250 person hours). Monitoring is an important component of adaptive management and is essential if we are to understand the ramifications of new silvicultural systems.

ABSTRACT Perforation design is an important aspect of the completion of production and injection wells. Significant penalties can be incurred both through productivity loss or additional perforation costs if the design is not accurately optimized. These penalties are especially severe in the case of high-rate gas wells. The Well Perforation Performance Model (PERF) was developed as a collaboration between SSI, London and BP Exploration, Aberdeen. It allows different perforating methods to be evaluated and compared to select the ideal gun and charge for a given perforation job. A major technical feature of the program is the finite element simulator, which allows accurate modelling of complex geometries. It can analyze great detail on small computers. The program allows the analysis to carried out in detail, using a state-of-the-art finite-element simulator, or more rapidly using a set of industry-standard nomographs. A database of gun and charge characteristics is provided, which records the results of API laboratory tests, so that typical perforating problems can easily be set up. The results, in terms of a productivity index or flow efficiency, can be viewed graphically as a function of the main physical parameters, including: Shot Density, Perforation Length and Diameter, Phasing, Damage and Compaction, Gravel Packing. Comparisons are provided against earlier published theoretical and experimental work, demonstrating improved accuracy and usability of the technology. INTRODUCTION Gun perforating has been one of the most successful completion methods to be used over the last fifty years or so. The aim of the process is to provide a lean flow channel between the wellbore and the producing formation, through the region of drilling-damaged reservoir.

This Paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). The material, as presented, does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. position of the Society of Petroleum Engineers, its officers, or members. Papers presented Papers presented at SPE meetings are subject to publication review by Editorial Committees of the Society of Petroleum Engineers. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Write Publications Manager, SPE, P.O. Box 833836, Richardson, TX 75083-3836 USA. Abstract Reservoir studies are often directed at specifically evaluating, amongst other things: The Sweep of Injected Water in a Waterflood, Tracing Injected Gas Though a Field, The Efficiency of a Polymer or Miscible Component Flood. Each of these problems can be completely obscured by the presence of numerical diffusion, which dominates and masks out true, physical saturation changes. No finite-difference method yet developed which relies on a fixed grid can claim to accurately model any sharp saturation front without degrading it eventually into a smooth, uniform distribution. It is pointless to try and remedy this by increasing the truncation accuracy of the scheme, since it is the physical dynamics of the approximation which are important. The basic difficulties in capturing and tracing any sharp saturation front with time are best understood by considering the fundamental property laws which are necessary for a physical solution. These are: Conservation Properties, Boundedness Properties, Transport Properties Properties, Boundedness Properties, Transport Properties and Shock Capture. We describe a method based on the finite-element scheme which allows these laws to be closely approximated. In addition, its formulation is such that it can be incorporated easily into existing IMPES black-oil and compositional simulators. The method is validated by comparison with one- and two-dimensional laboratory experiments and by numerical experiments designed to trap shock waves. Introduction Ever since Buckley and Leverett (1942) wrote down and analyzed the 1-D two-phase fluid flow problem in porous media, there has been a great deal of interest in porous media, there has been a great deal of interest in numerical methods which can accurately solve the equations under consideration. Even though exact analytical solutions can be found in the 1-D case, all the difficulties involved in numerical solution immediately become apparent. Indeed, no finite-difference method yet developed which relies on a fixed grid can claim to accurately model any sharp saturation front passing through the system without degrading it eventually into a smooth, uniform distribution [1]. As discussed in [1] it is pointless to try and remedy this by increasing the truncation accuracy of the scheme, since it is the dynamics of the approximation which are important. When 3-D problems are analyzed in a field scale reservoir simulator, these problems are frequently accentuated. Reservoir studies are often directed at specifically evaluating, amongst other things:The sweep of injected water in a waterfloodTracing injected gas through the field

Whereas the biology, physiology and systematics of mistletoes have been explored in considerable detail, their ecology has received less attention and our understanding is highly fragmentary. A conspicuous exception is the dwarf mistletoes (Arceuthobium spp.)—a genus that exclusively parasitises coniferous trees, including many commercially valuable species in the forests of the western United States. Accordingly, these plants have been the subjects of intensive cross-disciplinary research for the past five decades, initially from a control and management perspective but extending into most aspects of their ecology and life history. This review summarises our understanding of dwarf mistletoes, focusing on recent developments in the areas of mistletoe–wildlife interactions, fire, ecosystem ecology and conservation biology. We also compare dwarf mistletoes with Australian mistletoes in the genus Amyema, a diverse suite of species found throughout the continent. Despite fundamental differences in their evolutionary origin and most aspects of their autecology and life history, the genera exhibit many similarities in terms of their ecological role in forests and woodlands, and their influence on stand- and forest-scale dynamics. In particular, both groups provide nesting resources for a range of birds and mammals, and nutritional resources for a diverse assemblage of species. Both also interact with fire, potentially leading to changes in successional dynamics at the stand scale. At an applied level, both groups are widely considered as pests but, as our understanding of these keystone species improves, they have the potential to serve as sensitive ecological indicators for their respective ecosystems. Key research priorities are identified for further research on both groups of mistletoes and more explicit comparative research, with Arceuthobium serving as a valuable template for future work on Amyema and Australian mistletoes in general.

Long-term survival characteristics after resection for ampullary carcinoma are documented poorly. We have reviewed the clinical and histopathologic features of 23 long-term survivors who underwent resections between 1972 and 1984 (5-year survival rate, 52.1%). Twenty patients (87%) had intestinal type tumors and only two (9%) had papillary tumors. Associated adenomata were present in eight cases (35%) and distant ductular dysplasia was present in nine cases (39%). Long-term survival was correlated independently with tumor grade (P = 0.0031) and a new staging system that assesses local invasiveness (P = 0.0055). No correlation was found between survival and sex, tumor size, or presence of adenoma. Age was significant in univariate analysis (P = 0.0322) but not in multivariate analysis. A simple scoring system based on the grade and stage increased the predictability of survival (P = 0.0004). Application of this scoring system may allow an objective comparison of long-term survival results after resection from different series.

The allelopathic effects of Engelmann spruce bark and bark extacts on seed germination and seedling growth of several conifer species were examined. Extracts were hydroxystilbenes (isorhapontin and astringin) and condensed tannins. Experiments included the following: (i) seed germination in petri dishes with various concentrations of stilbenes and tannin–stilbenes; (ii) seed germination in petri dishes containing Engelmann spruce bark fragments; (iii) seedling growth in varying mixtures of peat/Engelmann spruce bark, the latter added either before or after seedling establishment; (iv) seedling growth in samples of Engelmann spruce forest soil horizons. In all experiments and in all species there was an allelopathic response to bark extracts. This response was expressed through inhibition of seed germination (seed-coat rupture and radicle emergence), necrotic discoloration and protoplasmic disruption of root-tip cells, suppression of root hairs, and repressed growth in general. Among the conifers tested Pinus ponderosa and Tsuga mertensiana appeared to be the most tolerant to bark extracts, Pinus contorta the most sensitive. Picea engelmannii was moderately sensitive.

Methyl 3,4-dihydro-4-oxo-1H-2-benzothiopyran-3-carboxylate (2)[or its tautomer (3)] has been obtained by Dieckmann cyclisation of methyl(o-methoxycarbonylbenzylthio)acetate. It reacts with hydrazine and with phenylhydrazine to give 1,2-dihydro-5H-[2]benzothiopyrano[4,3-c]pyrazol-3-one (7) and the 2-phenyl derivative (6), respectively, but does not give an isoxazolone with hydroxylamine. Methylation of the pyrazolone (6) with various reagents has been investigated.Methyl 6,7-dihydro-7-oxo-4H-thieno[3,2-c]thiopyran-6-carboxylate (12) and methyl and ethyl 3,4-dihydro-8-nitro-4-oxo-1H-thiopyrano[4,3-b][1]benzothiophen-3-carboxylate [(15) and (16) or their respective tautomers] have been obtained by the appropriate Dieckmann cyclisations. Compound (16) may also be obtained in a single step by treatment of 2-bromo-2′-chloro-5′-nitroacetophenone with ethyl mercaptoacetate (2 mol. equiv.). Improved procedures for carrying out some well known chemical transformations are described.

Le marche canadien des emissions de nouvelles actions : son efficacite comme mecanisme d'allocation du capital. La raison d'etre des marches de capitaux concerne la canalisation du capital financier des epargnants vers les investisseurs en capitaux reels. Le point central de la pr6sente etude se rattache a l'efficacite d'une partie du marche canadien des capitaux, a savoir les emissions de nouvelles actions ordinaires; ii s'agit la en effet d'un marche particulier ou se transigent des titres dont l'eventail de qualite est tres etendu. On juge de l'efficacite des marches de capitaux comme mecanismes d'allocation sur la base de leur fonctionnement quant a l'etablissement de taux de rendement equivalents pour des investissements comportant des degres de risque comparables, et de differences de taux proportionnelles aux differences des degres de risque. La propension a assumer des risques de la part des responsables des placements conditionne a la fois l'ampleur des fonds de placement disponibles et leur repartition entre les emprunteurs. Une propension tres elevee conduit a la necessite de primes au risque et donc de couts de financement pour les entreprises tres eleves, ce qui a pour resultat le rejet d'une grande proportion des projets d'investissement. Un tel etat de choses est evidemment defavorable au volume total des investissements et a la croissance de l'economie. Au Canada, durant les onze annees de la periode 1956-66, les entreprises industrielles, les compagnies d'utilites publiques, et les banques et autres institutions financieres ont obtenu des fonds d'un montant d'un milliard et huit/dixiemes de dollars ($1.8 milliard) au moyen d'emissions de nouvelles actions ordinaires. Ce montant n'inclut pas les emissions des fonds mutuels, ni les emissions a caractere speculatif dans les secteurs des mines et des petroles, ni les actions ordinaires faisant partie d'emissions de blocs de valeurs variees. Le test d'efficacite du marche met en cause la comparaison des evolutions des rendements des nouvelles emissions et de l'ensemble des actions en cours durant une periode determinee. Le marche est un mecanisme efficace d'allocation des capitaux financiers si les rendements des nouvelles actions et des actions en cours sont comparables, pour des categories d'actions comportant des degres de risque equivalents. L'auteur a calcule des indices de rendement pour toutes les emissions de nouvelles actions ordinaires durant la periode 1956-65. II a aussi analyse les memes emissions quant aux methodes de mise en vente et aux dimensions quantitatives et qualitatives des titres, pour arriver a determiner si le marche est un mecanisme qui permet d'identifier les potentialites de rendements associees a l'accroissement des ressources financieres obtenues par les entreprises. Les resultats empiriques offrent des elements de surprise. Les emissions de premiere qualite suivent systematiquement l'evolution du marche en general. Par contre, les emissions a haut degre de risque ne suivent pas l'evolution du marche en general; en fait, un nombre appreciable de ces emissions sont sans valeur a l'interieur d'une periode de cinq ans apres l'6mission. De fagon generale, les Canadiens semblent favorables a ces actions a haut degre de risque et fournissent des fonds aux entreprises qui les emettent a des conditions tres raisonnables. Cependant, ce marche particulier des actions a haut degre de risque n'est pas caracteristise par un degre d'efficacite tres grand.

Assumptions about customer loyalty underlie promotion, service, and location decisions of commercial banks. Young customers are sought through campus locations and special promotional programs on the premise that substantial continued patronage will result. Major advertising campaigns are launched, touting one bank as friendly, another as sincere, assuming such intangible appeals pull customers in, or, at a minimum, substantially reinforce current customers. Little is known about the bond between customer and bank, however, with the result that the payoffs of such marketing activities are uncertain. The purpose of this study is to provide basic information on that bond by addressing two main questions: (1) Do customers exhibit loyalty to their banks? and, if so, (2) What factors explain variations in the degree of loyalty observed? The results are based on a patronage tracking study conducted with graduates of a Canadian university. While the choice of sample somewhat restricts generalization, it made possible investigation of a third question: What is the influence of a "campus" branch location on subsequent bank patronage? The availability of banking facilities can clearly have an influence on customer loyalty. In this sense, the multibranch aspect of the Canadian banking system is important to appreciate. Canada's banking system is characterized by large national banks which operate branches across the country. Five major banks dominate. The three largest, the Royal Bank of Canada, the Canadian Imperial Bank of Commerce, and the Bank of Montreal, have over 1,000 branches each, while the two other majors, the Toronto-Dominion and Bank of Nova Scotia, each have about 750 branches. Although all banks are represented in every province, the regional coverage differs somewhat, particularly for the two smaller banks. These extensive branch systems can have opposing effects on customer loyalty. On the one hand, switching is facilitated since a customer who wants to change banks can easily locate a nearby alterna