bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation between radiculalgia and counts of T lymphocyte subsets in the peripheral blood of patients with lumbar disc herniation
Authors: Tian Peng , Ma Xin‐long , Wang Tao , Ma Jian‐xiong , Yang Xue
Published: October 2009

Objective:  To determine the correlation between the degree of radiculalgia and counts of T lymphocyte subsets in the peripheral blood of patients with lumbar disc herniation.

Methods:  Forty‐nine patients with lumbar disc herniation (group A) were divided into three subgroups according to Visual Analogue Scale (VAS) pain scores (group A1: n= 12, VAS 0–4.0; A2: n= 24, VAS 4.1–7.0; A3: n= 13, VAS 7.1–10.0. Twenty health blood donors who volunteered to be involved in the study comprised the control group (group B). Peripheral blood counts of various T lymphocyte subsets were measured in each group.

Results:  (i) The counts of CD4+ T and CD4+/CD8+ lymphocytes were higher in group A than in group B, and the difference between the two groups was statistically significant (P < 0.05). There were also statistically significant differences between group A and group B in the counts of CD3+ and CD8+ T lymphocytes (P < 0.05); (ii) There was no correlation between the VAS scores and the counts of CD3+ T lymphocytes (r= 0.194, P > 0.05). A strong significant correlation was observed between the VAS scores and counts of CD4+ T lymphocytes (r= 0.542, P < 0.05), CD4+/CD8+ (r= 0.468, P < 0.05), which increased with increasing VAS scores in the three subgroups of group A (P < 0.05). However there was a significant negative linear correlation between CD8+ T lymphocyte counts and pain scores (r=−0.462, P < 0.05).

Conclusion:  Our results suggest that changes in T lymphocyte subsets in peripheral blood take place after prolapse of lumbar intervertebral discs. The current results may provide support for involvement of immunologic mechanisms in low back pain secondary to herniation of the lumbar disc. T lymphocytes may play an important role in the development of symptoms in patients with lumbar intervertebral disc herniation.
Plasminogen activator inhibitor 1 gene polymorphisms and mirtazapine responses in Koreans with major depression
Authors: Chang Hun Soo , Lee Hwa‐Young , Ham Byung‐Joo , Kang Rhee‐Hun , Jeong Yoo‐Jung , Kim Hyang‐Mi , Hahn Sang‐Woo , Lee Min‐Soo
Published: October 2009

Introduction: Brain‐derived neurotrophic factor (BDNF) is involved in the pathophysiology of mental disorders and in the mechanism of action of antidepressant medications. The mature form of BDNF is derived from proBDNF through tissue type plasminogen activator (tPA) and the plasminogen system in the brain, which is regulated by an endogenous inhibitor, plasminogen activator inhibitor (PAI). Therefore, PAI may be involved in the development of major depressive disorder (MDD) and its response to antidepressant treatment. The present study determined the relationship between the 4G/5G polymorphism in the PAI1 gene and the clinical outcome of mirtazapine treatment in 271 Korean MDD patients.

Methods: We tested the association between the polymorphism and response to mirtazapine treatment or percentage decrease of the 21‐item Hamilton Depression Rating (HAMD21) scores using multiple logistic and linear regression analysis.

Results: PAI1 4G/5G genotypes and allele distributions were comparable between responders and non‐responders during the treatment period. Similarly, linear regression showed no association between genotypes or alleles and the percentage decline in total HAMD21 with mirtazapine treatment. In the analysis of symptomatic subscores, the percentage decline in the psychic anxiety and delusion scores after 4 weeks of mirtazapine treatment showed a statistical trend to a difference among genotypes, although it was not statistically significance.

Discussion: In this first pharmacogenetics study of the PAI1 4G/5G polymorphism and mirtazapine treatment response, our results do not support the hypothesis that this polymorphism is involved in the therapeutic response to mirtazapine.
Laparoscopic anterior resection for rectosigmoid cancer: Patient outcomes after implementation of a clinical pathway
Authors: Hsu T.W. , Chiang F.F. , Wang H.M.
Published: October 2009

Introduction: A clinical pathway designed for a single type of laparoscopic colorectal surgery for cancer might be helpful in decreasing complication rates and total hospital costs. It has been reported to be effective in reducing costs and shortening length of hospital stays in many situations such as laparoscopic cholecystectomy, colon resection, total colectomy, and gastrointestinal bleeding, as well as when caring for patients in the intensive care unit.

Materials and Methods: A clinical pathway, including surgical details and perioperative management, for patients undergoing laparoscopic anterior resection for rectosigmoid cancer was designed and implemented. From January 2003 to December 2006, it was applied to 80 patients.

Results: The average length of a hospital stay for these patients was 9.06 d. The mean hospital stay and total cost decreased year by year. The overall complication rate was 8.75% without perioperative mortality, and 47.5% of patients with underlying diseases were treated safely.

Discussion: Laparoscopic anterior resection for rectosigmoid cancer, with curative or palliative intent, was safe after standardization of surgical details and perioperative management. The total hospital costs for each patient was predictable and decreased year by year.
Making Science of Influencing: Assessing the Impact of Development Research
Authors: Sumner Andy , Ishmael‐Perkins Nick , Lindstrom Johanna
Published: October 2009

The impact and influence of development research is an agenda that has been gathering momentum over the last few years. This agenda is a coming together of two divergent concerns. The first, from the funders of research, draws on results based management and is concerned with getting value‐for‐money from research spending or with ‘more bang for the buck’. The second, more typical of those in the development studies research community, is concerned with whether research in the area is ‘making a difference’. Among development researchers there is also often a political or normative basis – addressing global poverty and inequality – and catalysing change.

The meanings of the terms' impact and influence are multiple, multi‐layered and complex to track. They may refer to use (i.e. consideration) or actual outcome(s) of social change. They can be visible or invisible; progressive or regressive. Impacts and influence can be intended or unintended and immediate or long‐term. The processes of impact and influence are acknowledged to be non‐linear, iterative and complex.

This paper considers the impact and influence of development research from a plurality of perspectives. Interest in the impact/influence of research projects aggregates upwards to support the overall case for (often public) funding of development research (in areas that are likely to play a major role in the next few years in changing the climate for public expenditure in light of the global financial crisis).
Predicting Erosion-Corrosion Induced by the Interactions Between Multiphase Flow and Structure in Piping System
Authors: Tang P. , Yang J. , Zheng J. Y. , Lam C. K. , Wong I. , He S. Z.
Published: October 2009

Erosion-corrosion failures frequently found in piping systems can lead to the leakage of pipes, or even damage of the whole system. Erosion-corrosion is a form of material degradation that involves electrochemical corrosion and mechanical wear processes encountered on the surface of metal pipes. Fluid-structure interactions have a profound influence on such erosion-corrosion phenomena. This paper is focused on the multiphase flow-induced erosion-corrosion phenomena in pipes, with multiscale analysis, to study the interactions between the flow and the protective film inside the piping system. The shear stress and the pressure of the flow in a pipe with a step were first obtained using a multiphase flow dynamic analysis. The erosion-corrosion rules of the pipes under the multiphase flow were then summarized. Using the microscale flow simulation method, the fluid-structure interaction between the flow and the protective film at the critical position was modeled. The deformation of the protective films was shown to vary with the flow velocity and the corresponding flow regime. According to the simulation results of the fluid-structure interaction, the location, rate, and extent of the erosion-corrosion on pipe surfaces can be predicted. The prediction was also proven by actual instances. Moreover, the method can be used in optimizing the design of the inner sleeves of pipes.
Mechanical Efficiency Optimization of a Sliding Vane Rotary Compressor
Authors: Huang Yuan Mao , Tsay San Nan
Published: October 2009

This study presents the mechanical efficiency optimization of a sliding vane rotary compressor by using genetic algorithms. Relevant air properties, volume segments, vane loadings and stresses, friction forces, compression power, and power loss are calculated to determine the mechanical efficiency of a compressor. Design variables include the major axis length and minor axis length of the elliptical stator inner contour, thickness, depth and width of vanes, mechanical efficiency, rotor rotational speed, polytropic exponent, and angular locations of the inlet and outlet ports. The effects of the mutation rate, crossover rate, and population size of the genetic algorithms on these design variables are studied. The vane is thin and the variation effects of vane dimensions on the mechanical efficiency of the compressor are less significant than other design variables. Therefore, the dimensions of vanes can be eliminated as design variables. The mechanical efficiency of the compressor is 0.55. The optimum values of these design variables are recommended for further development of the compressor.
Theoretical Analysis of Hydraulically Expanded Tube-to-Tubesheet Joints With Linear Strain Hardening Material Behavior
Authors: Laghzale Nor Eddine , Bouzid Abdel-Hakim
Published: October 2009

The mechanism of failure of tube-to-tubesheet joints is related to the level of stresses produced in the tube expansion and transition zones during the expansion process. Maintaining a lower bound limit of the initial residual contact pressure over the lifetime of the expanded joint is a key solution to a leak free joint. An accurate model that estimates these stresses can be a useful tool to the design engineer to select the proper material geometry combination in conjunction with the required expansion pressure. Most existing design calculations are based on an elastic perfectly plastic behavior of the expansion joint materials. The proposed model is based on a strain hardening with a bilinear material behavior of the tube and the tubesheet. The interaction of these two components is simulated during the whole process of the application of the expansion pressure. The effects of the gap and the material strain hardening are to be emphasized. The model results are validated and confronted against the more accurate numerical finite element analysis models. Additional comparisons have been made to existing methods.
Simplified Stress Categorization Using a Single Linear Elastic Analysis
Authors: Hossain M. M. , Reinhardt W. D. , Seshadri R.
Published: October 2009

The ASME Boiler and Pressure Vessel Code (code) provides guidelines for the classification of linear elastic stresses into primary, secondary, and peak stresses. Although these guidelines cover a wide range of pressure containing components, the guidelines are sometimes difficult to employ for three-dimensional components with complex geometry. This paper uses the mα-tangent method, an assessment of constraint in the component, based on limit load multiplier estimates as a stress classification tool. The method is applied to several practical pressure vessel components from simple to relatively complex geometric configurations. The results compare well with those obtained by conventional techniques, e.g., inelastic finite element analysis.
Modeling and Verification of Creep Strain and Exhaustion in a Welded Steam Mixer
Authors: Holmström Stefan , Rantala Juhani , Laukkanen Anssi , Kolari Kari , Keinänen Heikki , Lehtinen Olli
Published: October 2009

Structures operating in the creep regime will consume their creep life at a greater rate in locations where the stress state is aggravated by triaxiality constraints. Many structures, such as the welded steam mixer studied here, also have multiple material zones differing in microstructure and material properties. The three-dimensional structure as such, in addition to interacting material zones, is a great challenge for finite element analysis (FEA), even to accurately pinpoint the critical locations where damage will be found. The studied steam mixer, made of 10CrMo 9-10 steel (P22), has after 100,000 h of service developed severe creep damage in several saddle point positions adjacent to nozzle welds. FE-simulation of long term behavior of this structure has been performed taking developing triaxiality constraints, material zones, and primary to tertiary creep regimes into account. The creep strain rate formulation is based on the logistic creep strain prediction model implemented to ABAQUS, including primary, secondary, and tertiary creep. The results are presented using a filtering technique utilizing the formulation of rigid plastic deformation for describing and quantifying the developing “creep exhaustion.”
Evaluation of Glass and Basalt Fiber Reinforcements for Polymer Composite Pressure Piping
Authors: Mertiny Pierre , Juss Kulvinder , El Ghareeb Mohab M.
Published: October 2009

Pressure piping made from fiber-reinforced polymer composites is becoming increasingly popular. This development is driven by the need for lighter and more corrosion resistant components. Compared with traditional metallic structures, composites may satisfy these requirements without compromising strength or cost-effectiveness. The field of composite materials engineering is evolving rapidly, and new analysis and processing methods, as well as material systems, are continually emerging. The present contribution focuses on fiber reinforcements and their performance in pressurized tubular structures. Recently, basalt fiber has gained in popularity and in many cases has been considered an alternative to conventional fiber materials such as E- and S-glasses for composite piping. An investigation was conducted on the performance of basalt, E-glass, and S-glass reinforcements employing uniaxial tensile test rods and tubular samples. Specimens were produced by wet filament winding using a common thermoset epoxy polymer. In addition to rod sample rupture strength, the failure behavior and strength of tube specimens were assessed for leakage and bursting under different biaxial loading conditions. Two different methodologies for the assessment of leakage failures were described and discussed. Based on the experimental findings the performance of the various fiber reinforcements was evaluated.
Synthesis and hydrogen gas sensing properties of ZnO wirelike thin films
Authors: Hung Nguyen Le , Ahn Eunseong , Park Seongyong , Jung Hooncheol , Kim Hyojin , Hong Soon-Ku , Kim Dojin , Hwang Chanyong
Published: October 2009

The authors investigated the hydrogen gas sensing properties of the ZnO wirelike films synthesized by two consecutive steps: thermal oxidation of sputtered Zn metallic films in dry air. Structural characterization revealed that the authors synthesized polycrystalline wurtzite ZnO films of a wirelike structure with a width of less than 100nm and a length of several micrometers, possibly consisting of a chain of ZnO nanocrystallites with a mean granular size of 15nm. It was found from the gas sensing measurements that the ZnO wirelike films exhibited a maximum sensitivity, defined as a ratio of the change in conductance upon exposure to H2 gas in dry air over the conductance in dry air, ΔG∕Ga, of 283% to 200ppm H2 gas at a temperature of 200°C, indicating quite a possibility of much reduction in the operating temperature of the ZnO-based H2 gas sensors. The ZnO wirelike film sensors showed a fast response to hydrogen gas in comparison with conventional ZnO films. These results suggest that the ZnO wirelike films can be used as the gas sensing materials for low-cost and high-performance gas sensors.
Functional Repair of Human Donor Lungs by IL-10 Gene Therapy
Authors: Cypel Marcelo , Liu Mingyao , Rubacha Matt , Yeung Jonathan C. , Hirayama Shin , Anraku Masaki , Sato Masaaki , Medin Jeffrey , Davidson Beverly L. , de Perrot Marc , Waddell Thomas K. , Slutsky Arthur S. , Keshavjee Shaf
Published: October 2009

Treatment of damaged donor lungs with the cytokine interleukin-10 improves their function, allowing previously unacceptable organs to be used for transplantation.
Slowing Motor Neuron Degeneration, Naturally
Authors: Kelner Katrina L.
Published: October 2009

A naturally occurring blood protein slows the progression of ALS in mice engineered to carry the human mutation in the enzyme SOD-1.
Exquisitely Sensitive Imaging
Authors: LaMarco Kelly
Published: October 2009

Stimulated emission is used to achieve detection of light-absorbing moieties in biologically important molecules with undetectable fluorescence, such as hemoglobin.
Enhancing Chloride Transport
Authors: McDonald Heather B.
Published: October 2009

A drug that enhances CFTR ion channel activity improves chloride and water secretion from epithelial cells of cystic fibrosis patients.
The ABCs of the anterior cruciate ligament: a primer for magnetic resonance imaging assessment of the normal, injured and surgically repaired anterior cruciate ligament
Authors: Bining J , Andrews G , Forster B B
Published: October 2009

This article reviews the magnetic resonance imaging (MRI) findings of the native and reconstructed anterior cruciate ligament (ACL). MRI is the most accurate non-invasive modality to evaluate the ACL. Tears of the ACL manifest with direct and indirect signs. The reconstructed ACL has several complications including re-tear and anterior arthrofibrosis, which are also accurately assessed using MRI.
Aquaculture impacts on the algal and bacterial communities in a small boreal forest lakeThis paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”.
Authors: Findlay David L. , Podemski Cheryl L. , Kasian Susan E.M.
Published: October 2009

A whole-lake experiment to examine the impacts of aquaculture on a freshwater ecosystem was conducted at the Experimental Lakes Area in northwestern Ontario, Canada. From 2003 to 2006, a 10 tonne fish capacity aquaculture cage stocked with rainbow trout ( Oncorhynchus mykiss ) was operated in Lake 375 and the impact of excess nutrients on the algal and bacteria communities was examined. The experiment was designed as a nutrient loading experiment with fish food and fish excretion the source of nutrients. Total N and P concentrations increased over the 4 years (15× and 4×, respectively). Phytoplankton biomass increased 4× annually following the start of aquaculture operation in 2003. The most dramatic responses occurred during spring and fall mixing, with blooms of chrysophytes and dinoflagellates increasing biomass by up to 12×. Bacteria biomass and densities were unaffected except for increases in late fall. Periphyton biomass was relatively unaffected except for an increase in biomass in the fourth year. The combination of a long water residence time in the lake coupled with an extremely high fish stocking density in Lake 375 resulted in an immediate impact on water quality. The results suggest that the impacts of aquaculture are accumulative and continual stocking will further impact water quality.
Interspecies differences in biochemical, histopathological, and population responses in four wild fish species exposed to ethynylestradiol added to a whole lakeThis paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”.
Authors: Palace V. P. , Evans R. E. , Wautier K. G. , Mills K. H. , Blanchfield P. J. , Park B. J. , Baron C. L. , Kidd K. A.
Published: October 2009

Efforts to understand the effects of environmental estrogens on fish have shifted away from biochemical indicators towards population-level impacts. Ethynylestradiol (EE2) was added to a whole lake at environmentally relevant concentrations for 3 consecutive years to examine links between vitellogenin (VTG) induction, histopathological impacts, and population decline in four species of fish. VTG induction and histopathological effects in tissues were most severe in fathead minnow ( Pimephales promelas ) and pearl dace ( Margariscus margarita ). VTG was induced to a similar extent in lake trout ( Salvelinus namaycush ) but less so in white sucker ( Catostomus commersonii ). There were no histopathological effects in tissues of the two latter species. Population decline occurred in fathead minnows in the second year of EE2 additions and there were some indications of population decline in pearl dace during the third year. White suckers were not affected but lake trout declined in year 3. Habitat selection probably altered EE2 exposure and the different effects in each species likely also reflect differing sensitivities. It appears that VTG induction is not sufficient to predict effects of xenoestrogens on fish populations. However, stronger predictions can be made when VTG induction is assessed in conjunction with histopathological evidence of liver, kidney, and gonad tissue damage.
Performance of temperature and dissolved oxygen criteria to predict habitat use by lake trout (Salvelinus namaycush)This paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”.
Authors: Plumb John M. , Blanchfield Paul J.
Published: October 2009

We compared theoretical habitat volumes, determined from traditional combinations of temperature and dissolved oxygen concentration (DO) boundaries, with in situ habitat use by acoustically tagged lake trout ( Salvelinus namaycush ). The widely used criteria of 8–12 °C underestimated lake trout habitat use by 68%–80%. Instead, combined temperature (<12 or 15 °C) and DO (>4 or 6 mg·L–1) criteria most closely matched lake trout habitat use, had a similar seasonal trend as the tagged fish, suggested modest reductions (5% of total lake volume) in habitat during a warmer year, and performed best when the constraints of temperature and DO were most limiting. All data were collected in a small boreal shield lake (27 ha, zmax = 21 m) at the Experimental Lakes Area in northwestern Ontario, Canada, during two contrasting periods of thermal stratification (2003: warmer and longer; 2004: cooler and shorter), providing an assessment of observed and theoretical habitat volumes over current environmental extremes.
QSPR studies on normal boiling points and molar refractivities of organic compounds by correlation-ranking-based PCR and PC–ANN analyses of new topological indices
Authors: Ghavami Raouf , Najafi Amir , Hemmateenejad Bahram
Published: October 2009

The new topological indices (Sh indices) based on the distance sum and connectivity of a molecular graph, previously developed by our team, were extended to predict the two physicochemical properties, including normal boiling point (NBP) and molar refractivity (MR), of a large set of organic compounds consisting of alkanes, alkenes, ethers, amines, alcohols, alkylbenzenes, and alkylhalides. The sets of molecular descriptors were derived directly from the two-dimensional molecular structure of the compounds based on graph theory. Both linear and nonlinear modelings were implemented by using principal component regression (PCR) and principal component – artificial neural network (PC–ANN) with back-propagation learning algorithm, respectively. Eigenvalue and correlation-ranking procedures were used to rank the principal components and entered them into the models. Principal component analysis of Sh data matrix showed that the respective six and seven PCs could explain 97.49% and 99.22% of variances in the Sh indices. PCR analysis of the NBP and MR data demonstrated that the proposed Sh indices could explain about 97.52% and 99.52% of variations, while the variations explained by the PC–ANN modeling were more than 99.00% and 99.82%, respectively. The predictive ability of the models were evaluated using an external test set for NBP and MR of the molecules with the respective root-mean-square errors lower than 9.69 K and 0.660 cm3mol–1for the linear model and 6.17 K and 0.416 cm3mol–1for the nonlinear model.
Naturally occurring and synthetic polyyne glycosides
Authors: Pan Yanqing , Lowary Todd L. , Tykwinski Rik R.
Published: October 2009

Polyyne glycosides are a class of natural products that have been found in terrestrial plants, fungi, and marine algae. Many display interesting and potentially useful biological activities, which in some cases has initiated synthetic efforts toward their formation. This review provides a comprehensive report of polyyne glycosides isolated from natural sources, as well as the synthesis of these molecules and their analogues.
Synthesis and properties of ionic liquids based on 1-methyl-3-(2-phenethyl)imidazolium
Authors: Fakhraian Hossein , Gorgi-douze Azam
Published: October 2009

The synthesis and properties of three ionic liquids based on 1-methyl-3-(2-phenethyl)imidazolium cation ([MPIm]) and the chloride, tetrafluoroborate, and hexafluorophosphate anions have been investigated. The proposed quaternization and anion exchange processes afforded quantitative amounts of the three ionic liquids, and very pure [MPIm][BF4] and [MPIm][PF6] were obtained after recrystallization from ethanol. [MPIm][BF4] showed low melting point and high electrical conductivity. These ionic liquids (immiscible with diethyl ether but miscible with water and DMSO) absorb air moisture, increasing their mass and decreasing their viscosity. The results of NMR spectroscopy (1H, 13C, and 19F) and X-ray structure determination confirm the possibility of ion-pair and hydrogen-bond formation in [MPIm][BF4].
Cowaxanthone F, a new tetraoxygenated xanthone, and other anti-inflammatory and antioxidant compounds from Garcinia cowa
Authors: Panthong Kanda , Hutadilok-Towatana Nongporn , Panthong Ampai
Published: October 2009

A new tetraoxygenated xanthone, cowaxanthone F (1), as well as four known compounds, morelloflavone (2), volkensiflavone (3), morelloflavone-7″-O-glucoside (fukugiside, 4), and 1,6-dihydroxyxanthone (5), were isolated from the crude acetone extract of the twigs of Garcinia cowa (Guttiferae). All compounds (1–5) were tested for antioxidant activity against DPPH (diphenylpicrylhydrazyl), hydroxyl, and superoxide radicals; only morelloflavone (2) and morelloflavone-7″-O-glucoside (4) exhibited high potency. Eight tetraoxygenated xanthones from the fruits of G. cowa , cowaxanthones A–D (6–9), cowanin (15), α-mangostin (16), mangostanin (17), and cowanol (18), were also investigated for anti-inflammatory activity using ethyl phenylpropiolate (EPP)-induced ear edema. Assessment at 30, 60, and 120 min revealed that cowaxanthones B–D (7–9), cowanin (15), and α-mangostin (16) exhibited significant anti-inflammatory activity when compared to phenylbutazone, while cowaxanthone A (6), mangostanin (17), and cowanol (18) showed less activity.
Structural control of Au and Au–Pd nanoparticles by selecting capping ligands with varied electronic and steric effects
Authors: Murphy Patrick B. , Liu Feng , Cook Stephen C. , Jahan Nusrat , Marangoni D. Gerrard , Grindley T. Bruce , Zhang Peng
Published: October 2009

Weakly interacting ligands including three Gemini surfactants, didodecyldimethylammonium bromide (DDAB), and amines (RNH2, R2NH, and R3N) were used to prepare Au nanoparticles (NPs). Aqueous Au NPs capped with DDAB and Gemini surfactants showed similar sizes (3–4 nm), whereas toluene-based NPs stabilized with DDAB, amines, and their mixtures range from 2.5 to 9.3 nm. Ligand effect on Au–Pd NP structure was also studied with EXAFS. These findings were consistently accounted for by considering the ligand’s electronic/steric effects and mixed ligands coadsorption, and suggest useful ways to control NP structure by manipulating the two effects and using mixed capping ligands.
Water-promoted regioselective hydrothiolation of alkynes
Authors: Bhadra Sukalyan , Ranu Brindaban C.
Published: October 2009

Water promotes hydrothiolation of unactivated alkynes efficiently without any catalyst or additive. The reaction at room temperature furnishes vinyl sulfides with high regioselectivity via anti-Markovnikov addition. The terminal alkynes provide dithiolanes at 80 °C by bis-addition. The reactions are very clean and high yielding.
Can plant productivity be increased by inoculation of tree roots with soil microorganisms?
Authors: Torrey John G.
Published: October 2009

Fostering symbiotic associations between appropriate soil microorganisms and their compatible hosts lies within the management capabilities of agriculturalists and foresters. Using knowledge of the fundamental scientific bases for these associations, one can facilitate the development of beneficial symbioses by inoculation of seeds, seedlings, or growing plants with selected microorganisms to establish and perpetuate effective symbioses leading to increased productivity. Of particular interest to the forester are four major groups of symbiotic associations: Rhizobium or Bradyrhizobium–leguminous trees; Frankia–actinorhizal plants; ectomycorrhizae–host trees; and endomycorrhizae–host trees, including vesicular–arbuscular mycorrhizae. Summarized here are the isolation, characterization, and culture of the microbial symbionts; the demonstrated specificity for infection and effectivity for facilitating nutrient uptake in each case; and the development of the technology for field inoculation to achieve effective symbioses in forest plantations. The factors involved in successful inoculation procedures are reviewed, and recommendations are made as to some of the necessary steps to further the development of this biotechnology.
The relations between chemical composition of oak tree rings, leaf, bark, and soil solution in a partly mixed stand
Authors: Visser P.H.B. De
Published: October 2009

The elemental composition of oak (Quercusrobur L.) tree rings was studied along a vertical gradient in trees situated on three different soils. High concentrations of N, P, K, Mg, S, and Mn were observed in the last 15 annual rings relative to older rings and were related to the transition from sapwood to heartwood. In the sapwood, a strong gradient of N, P, S, and Mn was observed and was partly related to high concentrations of Mn2+, NH4+, and NO3− in the soil solution. No significant changes in concentration of other elements within the sapwood occurred. Manganese content in wood and leaves corresponded to Mn2+ concentrations in the soil solution for the 5 years examined. Differences in soil availability of Al and Ca were not reflected in stemwood composition, yet in branches and leaves Ca content was influenced.
Growth of southern pine beetle associated fungi in relation to the induced wound response in loblolly pine
Authors: Ross Darrell W. , Fenn Patrick , Stephen Frederick M.
Published: October 2009

Growth of the three major fungal associates of Dendroctonusfrontalis Zimmermann in Pinus taeda L. phloem was evaluated with respect to development of the wound-induced lesion following artificial inoculations. Ophiostomaminus (Hedge.) H. & P. Syd. and Ceratocystiopsisranaculosus Perry et Bridges were isolated from apparently healthy phloem 2 cm outside the margin of the visible wound-induced lesion up to 28 days after inoculation. Ophiostomaminus was isolated more often than C. ranaculosus from outside the lesion, and both fungi were isolated less often from outside the lesion with increasing time after inoculation. SJB 122 was never isolated from outside the wound-induced lesion. All fungi were isolated more often adjacent to the inoculation site than at the lesion margin or outside the lesion, and these differences were generally greater with increasing time after inoculation. Following combined inoculations, O. minus inhibited the growth of both mycangial fungi, while C. ranaculosus appeared to inhibit the growth of SJB 122. Inoculations with heat-killed O. minus and C. ranaculosus and two nonpine plant pathogens, Ceratocystisfagacearum (Bretz) Hunt and Hypoxylonatropunctatum (Schw. ex Fr.) Cke., failed to provide strong evidence of chemical elicitors that may stimulate lesion formation in the absence of living fungi capable of growing in the host tissues. Ophiostomaminus grew at least 1.5 cm into the sapwood after 26 days, while C. ranaculosus grew less than 0.5 cm into the sapwood during the same period of time.
Effect of site characteristics and 1st- and 2nd-year seedling densities on forest development in a northern hardwood forest
Authors: Thurston Sally W. , Krasny Marianne E. , Martin C. Wayne , Fahey Timothy J.
Published: October 2009

Factors influencing the initial colonization and subsequent (18-year) survivorship of trees were studied in two clear-cut watersheds in the Hubbard Brook Experimental Forest in New Hampshire. Variation in microsite conditions associated with the harvest operations (e.g., soil scarification, slash) and physical gradients within the watershed were particularly important in determining 1st- and 2nd-year densities of pin cherry (Prunuspensylvanica L.) and yellow birch (Betulaalleghaniensis Britt.), whereas factors relating to seed availability and the presence of advance seedlings and sprouts were important in determining 1st- and 2nd-year white ash (Fraxinusamericana L.) density. The 1st- and 2nd-year densities of sugar maple (Acersaccharum Marsh.) and beech (Fagusgrandifolia Ehrh.) were relatively independent of factors measured in this study and were probably related to both seed availability and the presence of advance seedlings and sprouts. Physical site factors immediately following clear-cutting continued to be important in determining the density of pin cherry and yellow birch at stand age 18 years, whereas 2nd-year sugar maple and beech seedling and sprout densities were the most important factors in determining the densities of these species 18 years following clear-cutting.
Persistence of Laccaria spp. as ectomycorrhizal symbionts of container-grown black spruce
Authors: Buschena C.A. , Doudrick R.L. , Anderson N.A.
Published: October 2009

Piceamariana (Mill.) B.S.P. seedlings were grown in containers under three levels of N–P–K fertilization. They were inoculated with one of three levels of mycelial slurry of either an isolate of Laccariabicolor (Maire) Orton or of Laccarialongipes G.M. Mueller. Seedlings were grown for 16 weeks in a glasshouse before planting on two different sites (organic and mineral soil) in northern Minnesota. Persistence of the two fungi was monitored over a 2.5-year period. Dikaryotic-monokaryotic pairings indicated that trees on the mineral soil site, inoculated with L. bicolor, remained colonized by that isolate for the entire test period. Controls and L. longipes treated seedlings on the same mineral soil site became colonized by indigenous isolates of L. bicolor. The half-strength fertilizer treatment produced significantly taller seedlings.
Effects of long-term pruning, meristem origin, and branch order on the rooting of Douglas-fir stem cuttings
Authors: Copes Donald L.
Published: October 2009

The rooting percentages of 14 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) clones were examined annually from 1974 to 1988. The trees were 10 and 13 years old in 1974 and were pruned to 2.0 m in 1978 and 1979 and then recut annually to 0.5, 1.0, or 1.5 m, starting in 1983. The pruned trees showed no evidence of decreased rooting percentage even after 15 years; average rooting increased from 47% in 1974 to 74% in 1986. Rooting percentage was significantly influenced by tree height. Cuttings collected from 0.5 m tall ramets exhibited better rooting than cuttings from 1.0 or 2.0 m tall ramets, and cuttings from 1.0 m tall ramets rooted better than cuttings from 2.0 m tall ramets. Rooting of cuttings collected from 0.5 m high subinterval zones within trees showed a negative linear relation between rooting percentage and collection height. Cuttings collected from the 0–0.5 m zone rooted 25% better than cuttings from the 1.5–2.0 m zone of the 2 m tall trees. That difference was significant at p < 0.05. A test of rooting of larger, more orthotropic cuttings gathered from the upper flat surface of pruned ramets indicated that the cuttings from the top rooted significantly less than smaller, more plagiotropic cuttings from the contiguous side areas (24 versus 33%, respectively). Rooting comparisons of meristems of primary and secondary origin showed significantly greater rooting of secondary meristems. Comparison of rooting of second-order and first-order meristems of secondary origin indicated the second-order twigs averaged 26% better rooting than the first-order branch tips when the cuttings were collected in January and placed in the rooting beds in February.
Effect of ozone and aluminum on pitch pine (Pinusrigida) seedlings: anatomy of mycorrhizae
Authors: McQuattie Carolyn J. , Schier George A.
Published: October 2009

Newly germinated pitch pine (Pinusrigida Mill.) seedlings inoculated with a mycorrhizal fungus (Pisolithustinctorius (Pers.) Coker & Couch) were grown for 13 weeks in sand irrigated with nutrient solution (pH 4.0) containing 0, 12.5, 25, or 50 mg/L aluminum (Al) in growth chambers fumigated with 0, 50, 100, or 200 ppb ozone. Anatomical changes in roots stressed by ozone and Al, singly and in combination, were determined by light and electron microscopy. All ozone concentrations reduced the percentage of mycorrhizal colonization. In contrast, Al increased the percentage of colonization at low concentration, reducing it only at the highest level. Aluminum caused more overall deterioration of root cortex than ozone, though both treatments adversely affected the mycorrhizal fungus. Increased vacuolation in the root meristem was caused by both ozone and Al. Additional effects of ozone on cells in the meristem were the swelling of the nuclear membrane and invaginations in the plasmalemma. Intracellular fungal hyphae were observed at the highest level of ozone and (or) Al. The combined effect of ozone and Al on the anatomy of mycorrhizae was greater (possibly synergistic) than the effect of each pollutant alone. Similar cellular alterations have also been observed in forests damaged by pollution.
An examination of regional, provenance, and family variation in cold hardiness of Pinusmonticola
Authors: Thomas Barbara R. , Lester Donald T.
Published: October 2009

Seedlings from 29 seed lots of western white pine (Pinusmonticola Dougl. ex D. Don) from the British Columbia coast and interior ranges were tested for frost hardiness. Detached needles were exposed to a series of freezing temperatures, and relative hardiness was calculated based on visual scoring of injury. Seasonal progress in hardening was tested in seedlings maintained at the University of British Columbia (coastal) nursery. In addition, the same seed lots grown at a coastal and an interior field plantation were tested once during the hardening process. There was a significant (p = 0.04) regional difference between the coast and interior sources. The coastal region showed approximately 20% more damage than the interior region. Whereas provenances within a region did not differ in cold hardiness, families within a provenance did vary in this respect. The results suggest that the role of phenotypic plasticity in cold hardiness of P. monticola is reduced relative to other traits. It is recommended that seed transfer be restricted to within coastal and interior regions and that collections be bulked within a region.
A comparison of two tree-ring-index standardization techniques
Authors: Murphy J.O. , Palmer J.G.
Published: October 2009

A comparison is made between two tree-ring index chronologies that are based on the same set of site ring measurements but use two different standardization techniques. Both polynomial functions and 50-year Gaussian filtering procedures have been employed to represent the biological growth curve, thereby essentially detrending the resulting ring-index chronologies. It is established that although both approaches generate highly correlated time series at lag 0, significant differences exist in the autocorrelation functions, mean sensitivity values, and spectral amplitudes at the low frequency end of the spectrum. The exclusion of these periodicities is of concern, as they are normally associated with longer term climatic variations as well as site influences. Consequently, the nature of the descriptive statistical indicators generally considered, especially the spectral profile, should be established in conjunction with possible standardization options. Also, it would be prudent to appraise existing chronologies, on the same basis, prior to undertaking any dendrochronological applications.
Genetic structure and variability in jack pine populations: effects of insularity
Authors: Gauthier Sylvie , Simon Jean-Pierre , Bergeron Yves
Published: October 2009

To determine the effects of insularity on the genetic structure and variability of jack pine (Pinusbanksiana Lamb.) populations at a regional scale, stands from two different landscapes were studied: two islands in a lake and two mainland areas. The two landscapes have been affected by different fire regimes. The genetic structure and variability of the four populations were analyzed using cellulose acetate gel electrophoresis of 11 enzyme systems. The analysis of 22 loci showed an average polymorphism of 60.0%, a mean of 2.3 alleles per locus, a mean of 1.185 effective alleles per locus, and an observed level of heterozygosity of 0.171. The Fis values (i.e., fixation index of individuals relative to their population) for all but two loci indicated an excess of heterozygotes compared with the expected numbers under Hardy–Weinberg equilibrium. The genetic differentiation among populations was weak (Fst = 0.018). There were no significant differences among the four populations for five genetic parameters (mean number of alleles per locus, mean number of effective alleles per locus, percentage of polymorphic loci, and observed or expected heterozygosity). Although the allelic frequencies were homogeneous between island populations, a significant heterogeneity in allele frequencies was observed between mainland populations. The results suggest that gene flow in island populations is sufficiently high to maintain a level of genetic variability similar to that found in mainland populations and to counteract the effect of isolation and differential selective pressures resulting from different disturbance regimes.
Application des modèles statistiques spatio-temporels aux échantillonnages forestiers successifs
Authors: Houllier François , Pierrat Jean-Claude
Published: October 2009

When surveying the same forest on several successive occasions, sampling intensity may be reduced without any loss of precision by taking into account the spatial and temporal structures of the estimated variable. The theory of regionalized variables (RV) generalizes and improves the estimators derived from the classical sampling with partial replacement (SPR) theory. A general model accounting for both temporal and spatial structures is presented in the context of successive inventories. The best linear unbiased estimators (Blue) are derived by using the kriging technique. A comparison of RV and SPR estimators on a simple numerical example reveals that the variance can be overestimated with the classical estimators. An application to a forest decline survey illustrates how this theory may be used to choose and optimize a sampling strategy. Finally, the general interest as well as some practical problems of RV theory are discussed.
Pascal's recurrence relation and even-aged-forest stand dynamics
Authors: Leary Rolfe A. , Phan Hien , Nimerfro Kevin
Published: October 2009

A common method of modelling forest stand dynamics is to use permanent growth plot remeasurements to calibrate a whole-stand growth model expressed as an ordinary differential equation. To obtain an estimate of future conditions, either the differential equation is integrated numerically or, if analytic, the differential equation is solved in closed form. In the latter case, a future condition is obtained simply by evaluating the integral form for the age of interest, subject to appropriate initial conditions. An older method of modelling forest stand dynamics was to use a normal or near-normal yield table as a density standard and calibrate a relative density change equation from permanent plot remeasurements. An estimate of a future stand property could be obtained by iterating from a known initial relative density. In this paper we show that when the relative density change equation has a particular form, the historical method also has a closed form solution, given by a sequence of polynomials with coefficients from successive rows of Pascal's arithmetic triangle.
The relative importance of competition, microsite, and climate in controlling the stem taper and profile shape in jack pine
Authors: Morris Dave M. , Forslund R.R.
Published: October 2009

The purpose of this study was to identify the relative importance that environmental factors have on the taper and profile shape of mature jack pine (Pinusbanksiana Lamb.) stems. A total of 60 dominant trees from six different stands (10 per stand) were felled and measured to determine stem size, taper, and profile shape. Total height, basal age, and diameters at three locations (breast height, 20% total height, and 70% total height) were collected. The last two diameters were then used to calculate stem taper and profile shape. Data on competition (4 variables) and microsite (10 variables) were collected. Climatic variables (6) were interpolated from nearby weather station data. From the regression results, several environmental factors from all three categories (competition, microsite, and climate) proved to be important in determining taper and shape. The most relevant measures from each category, respectively, were percent canopy opening (taper) or total basal area (shape), slope, and growing degree-days. When combined in a multiple linear regression, these environmental variables, along with stand age, explained 61.9% of the variation in stem taper and 38.6% in stem shape. Although these values represent a significant portion of the variation in stem profile characteristics, further exploration into additional factors (e.g., bending and stress caused by wind action, nutrition, genetics) affecting stem taper and shape is required.