bluuebunny/crossref_metadata_2025 huggingface dataset:
The physical therapist’s role in physical activity promotion
Authors: Verhagen E , Engbers L
Published: October 2008

Clinicians are increasingly confronted with the diseases of physical inactivity. Paradoxically, a promising strategy to motivate sedentary individuals to become more active is the opportunity to encourage physical activity related behavioural change when individuals encounter health professionals. Although health care professionals trained in exercise prescription are recognised as having the potential to play an important role in promoting regular physical activity, their role has been minimal in multidisciplinary approaches to date. Even so, the role of physical therapists has gone largely unrecognised. Nevertheless, because of their training and experience, physical therapists are ideally placed to promote the health and well being of individuals and the general public through physical activity and exercise prescription. Therefore, physical therapists, general practitioners and other caregivers alike should become aware of the physical therapist’s potential in promoting safe and healthy physical activity.
VirB8: a conserved type IV secretion system assembly factor and drug targetThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.
Authors: Baron Christian
Published: October 2008

Type IV secretion systems are used by many Gram-negative bacteria for the translocation of macromolecules (proteins, DNA, or DNA–protein complexes) across the cell envelope. Among them are many pathogens for which type IV secretion systems are essential virulence factors. Type IV secretion systems comprise 8–12 conserved proteins, which assemble into a complex spanning the inner and the outer membrane, and many assemble extracellular appendages, such as pili, which initiate contact with host and recipient cells followed by substrate translocation. VirB8 is an essential assembly factor for all type IV secretion systems. Biochemical, cell biological, genetic, and yeast two-hybrid analyses showed that VirB8 undergoes multiple interactions with other type IV secretion system components and that it directs polar assembly of the membrane-spanning complex in the model organism Agrobacterium tumefaciens. The availability of the VirB8 X-ray structure has enabled a detailed structure–function analysis, which identified sites for the binding of VirB4 and VirB10 and for self-interaction. Due to its multiple interactions, VirB8 is an excellent model for the analysis of assembly factors of multiprotein complexes. In addition, VirB8 is a possible target for drugs that target its protein–protein interactions, which would disarm bacteria by depriving them of their essential virulence functions.
PRAF1: a Golgi complex transmembrane protein that interacts with virusesThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.
Authors: Compton Shannon L. , Behrend Ellen N.
Published: October 2008

Prenylated Rab acceptor domain family member 1 (PRAF1), a transmembrane protein whose precise function is unknown, localizes to the Golgi complex, post-Golgi vesicles, lipid rafts, endosomes, and the plasma membrane. VAMP2 and Rab3A are SNARE proteins that interact with PRAF1, and, as part of a SNARE complex, PRAF1 may function in the regulation of docking and fusion of transport vesicles both in the Golgi complex and at the plasma membrane. Alternately, PRAF1 may function as a sorting protein in the Golgi complex. In addition to interacting with SNARE proteins, PRAF1 interacts with rotaviral, retroviral, and herpes viral proteins. The function of viral protein interaction is unknown, but PRAF1 may enhance rotaviral and retroviral assembly. In contrast, PRAF1 may inhibit the herpes virus life cycle.
Strategies for dealing with conformational sampling in structural calculations of flexible or kinked transmembrane peptidesThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.
Authors: Rainey Jan K. , Fliegel Larry , Sykes Brian D.
Published: October 2008

Peptides corresponding to transmembrane (TM) segments from membrane proteins provide a potential route for the determination of membrane protein structure. We have determined that 2 functionally critical TM segments from the mammalian Na+/H+ exchanger display well converged structure in regions separated by break points. The flexibility of these break points results in conformational sampling in solution. A brief review of available NMR structures of helical membrane proteins demonstrates that there are a number of published structures showing similar properties. Such flexibility is likely indicative of kinks in the full-length protein. This minireview focuses on methods and protocols for NMR structure calculation and analysis of peptide structures under conditions of conformational sampling. The methods outlined allow the identification and analysis of structured peptides containing break points owing to conformational sampling and the differentiation between oligomerization and ensemble-averaged observation of multiple peptide conformations.
Partitioning of myelin basic protein into membrane microdomains in a spontaneously demyelinating mouse model for multiple sclerosisThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.
Authors: DeBruin Lillian S. , Haines Jeffery D. , Bienzle Dorothee , Harauz George
Published: October 2008

We have characterized the lipid rafts in myelin from a spontaneously demyelinating mouse line (ND4), and from control mice (CD1 background), as a function of age and severity of disease. Myelin was isolated from the brains of CD1 and ND4 mice at various ages, and cold lysed with 1.5% CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulphonate). The lysate was separated by low-speed centrifugation into supernatant and pellet fractions, which were characterized by Western blotting for myelin basic protein (MBP) isoforms and their post-translationally modified variants. We found that, with maturation and with disease progression, there was a specific redistribution of the 14–21.5 kDa MBP isoforms (classic exon-II-containing vs exon-II-lacking) and phosphorylated forms into the supernatant and pellet. Further fractionation of the supernatant to yield detergent-resistant membranes (DRMs), representing coalesced lipid rafts, showed these to be highly enriched in exon-II-lacking MBP isoforms, and deficient in methylated MBP variants, in mice of both genotypes. The DRMs from the ND4 mice appeared to be enriched in MBP phosphorylated by MAP kinase at Thr95 (murine 18.5 kDa numbering). These studies indicate that different splice isoforms and post-translationally modified charge variants of MBP are targeted to different microdomains in the myelin membrane, implying multifunctionality of this protein family in myelin maintenance.
The role of SLAM family receptors in immune cell signalingThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.
Authors: Ostrakhovitch Elena A. , Li Shawn S.-C.
Published: October 2008

The signaling lymphocyte-activating molecule (SLAM) family immunoreceptors are expressed in a wide array of immune cells, including both T and B lymphocytes. By virtue of their ability to transduce tyrosine phosphorylation signals through the so-called ITSM (immunoreceptor tyrosine-based switch motif) sequences, they play an important part in regulating both innate and adaptive immune responses. The critical role of the SLAM immunoreceptors in mediating normal immune reactions was highlighted in recent findings that SAP, a SLAM-associated protein, modulates the activities of various immune cells through interactions with different members of the SLAM family expressed in these cells. Importantly, mutations or deletions of the sap gene in humans result in the X-linked lymphoproliferative syndrome. In this review, we summarize current knowledge and survey the latest developments in signal transduction events triggered by the activation of SLAM family receptors in different cell types.
Recent progress in structure–function analyses of Nramp proton-dependent metal-ion transportersThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.
Authors: Courville P. , Chaloupka R. , Cellier M.F.M.
Published: October 2008

The natural resistance-associated macrophage protein (Nramp) homologs form a family of proton-coupled transporters that facilitate the cellular absorption of divalent metal ions (Me2+, including Mn2+, Fe2+, Co2+, and Cd2+). The Nramp, or solute carrier 11 (SLC11), family is conserved in eukaryotes and bacteria. Humans and rodents express 2 parologous genes that are associated with iron disorders and immune diseases. The NRAMP1 (SLC11A1) protein is specific to professional phagocytes and extrudes Me2+from the phagosome to defend against ingested microbes; polymorphisms in the NRAMP1 gene are associated with various immune diseases. Several isoforms of NRAMP2 (SLC11A2, DMT1, DCT1) are expressed ubiquitously in recycling endosomes or specifically at the apical membrane of epithelial cells in intestine and kidneys, and can contribute to iron overload, whereas mutations impairing NRAMP2 function cause a form of congenital microcytic hypochromic anemia. Structure–function studies, using various experimental models, and mutagenesis approaches have begun to reveal the overall transmembrane organization of Nramp, some of the transmembrane segments (TMS) that are functionally important, and an unusual mechanism coupling Me2+and proton H+transport. The approaches used include functional complementation of yeast knockout strains, electrophysiology analyses in Xenopus oocytes, and transport assays that use mammalian and bacterial cells and direct and indirect measurements of SLC11 transporter properties. These complementary studies enabled the identification of TMS1and 6 as crucial structural segments for Me2+and H+symport, and will help develop a deeper understanding of the Nramp transport mechanism and its contribution to Me2+homeostasis in human health and diseases.
P-glycoprotein (ABCB1) interacts directly with lipid-based anti-cancer drugs and platelet-activating factorsThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.
Authors: Eckford Paul D.W. , Sharom Frances J.
Published: October 2008

The P-glycoprotein multidrug transporter (Pgp; ABCB1) is an ATP-binding cassette (ABC) protein that has been implicated in the multidrug resistance of human cancers. Pgp couples ATP hydrolysis to active extrusion from the cell of a broad array of amphipathic compounds via an ill-defined mechanism. Substrates are believed to interact with Pgp within the membrane. Reconstituted Pgp functions as an ATP-dependent flippase for a variety of fluorescently labelled membrane lipids. The protein may also function as a drug ‘flippase’, moving its substrates from the inner to the outer leaflet of the bilayer. We show that lipid-based anti-cancer drugs, such as miltefosine, and signaling molecules, such as platelet-activating factors, bind saturably to Pgp with Kdvalues in the low micromolar range, and modulate its ATPase activity. These compounds also inhibit Pgp-mediated flipping of fluorescent lipids and transport of Hoechst 33342 and tetramethylrosamine, which occupy different subsites in the drug-binding pocket. Bacterial lipid A modulates Pgp ATPase activity, and glycolipid flipping is inhibited by unlabelled glucosylceramide, suggesting that these lipids also interact with the transporter. These results indicate that Pgp treats a variety of lipid-based molecules as substrates, and likely interacts with lipids and drugs in the same manner.
Unraveling trafficking of the kidney anion exchanger 1 in polarized MDCK epithelial cellsThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.
Authors: Cordat Emmanuelle
Published: October 2008

Kidney anion exchanger 1 (kAE1) is a membrane glycoprotein expressed at the basolateral membrane of type A intercalated cells in the kidney collecting tubule. Mutations occurring in the gene encoding this protein can give rise to distal renal tubular acidosis (dRTA), a disease characterized by an impaired urine acidification, nephrocalcinosis, and renal failure. Here we review how the study of dRTA mutants in polarized epithelial cells has shed light on the cellular mechanisms resulting in this renal disease.
Defects in cytochrome oxidase assembly in humans: lessons from yeastThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.
Authors: Zee Jennifer M. , Glerum D. Moira
Published: October 2008

The biogenesis of the inner mitochondrial membrane enzyme cytochrome c oxidase (COX) is a complex process that requires the actions of ancillary proteins, collectively called assembly factors. Studies with the yeast Saccharomyces cerevisiae have provided considerable insight into the COX assembly pathway and have proven to be a fruitful model for understanding the molecular bases for inherited COX deficiencies in humans. In this review, we focus on critical steps in the COX assembly pathway. These processes are conserved from yeast to humans and are known to be involved in the etiology of human COX deficiencies. The contributions from our studies in yeast suggest that this organism remains an excellent model system for delineating the molecular mechanisms underlying COX assembly defects in humans. Current progress suggests that a complete picture of COX assembly will be achieved in the near future.
K–Cl cotransport in red blood cells from patients with KCC3 isoform mutantsThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.
Authors: Lauf P.K. , Adragna N.C. , Dupre N. , Bouchard J.P. , Rouleau G.A.
Published: October 2008

Red blood cells (RBCs) possess the K–Cl cotransport (KCC) isoforms 1, 3, and 4. Mutations within a given isoform may affect overall KCC activity. In a double-blind study, we analyzed, with Rb as a K congener, K fluxes (total flux, ouabain-sensitive Na+/K+ pump, and bumetanide-sensitive Na–K–2Cl cotransport, Cl-dependent, and ouabain- and bumetanide-insensitive KCC with or without stimulation by N-ethylmaleimide (NEM) and staurosporine or Mg removal, and basal channel-mediated fluxes, osmotic fragility, and ions and water in the RBCs of 8 controls, and of 8 patients with hereditary motor and sensory neuropathy with agenesis of corpus callosum (HMSN–ACC) with defined KCC3 mutations (813FsX813 and Phe529FsX532) involving the truncations of 338 and 619 C-terminal amino acids, respectively. Water and ion content and, with one exception, mean osmotic fragility, as well as K fluxes without stimulating agents, were similar in controls and HMSN–ACC RBCs. However, the NEM-stimulated KCC was reduced 5-fold (p < 0.0005) in HMSN–ACC vs control RBCs, as a result of a lower Vmax (p < 0.05) rather than a lower Km (p = 0.109), accompanied by corresponding differences in Cl activation. Low intracellular Mg activated KCC in 6 out of 7 controls vs 1 out of 6 HMSN–ACC RBCs, suggesting that regulation is compromised. The lack of differences in staurosporine-activated KCC indicates different action mechanisms. Thus, in HMSN–ACC patients with KCC3 mutants, RBC KCC activity, although indistinguishable from that of the control group, responded differently to biochemical stressors, such as thiol alkylation or Mg removal, thereby indirectly indicating an important contribution of KCC3 to overall KCC function and regulation.
Patterns of balsam fir mortality caused by an uncontrolled spruce budworm outbreak
Authors: MacLean David A. , Ostaff Donald P.
Published: October 2008

Tree mortality caused by spruce budworm (Choristoneurafumiferana (Clem.)) defoliation was assessed annually from 1976 to 1985 in 20 mature balsam fir (Abiesbalsamea (L.) Mill.) stands on Cape Breton Island, Nova Scotia, and was related to defoliation and to tree, stand, and site characteristics. Ten to 12 years after the start of the budworm outbreak, fir mortality averaged 87% of the merchantable volume (range 60–100%) among the stands. Timing of mortality was similar to that found in studies of previous outbreaks. In the first 4 years of the outbreak, virtually all the trees that died had more than 90% cumulative defoliation but, overall, 64, 21, and 14% of the dead trees had cumulative defoliation >90, 76 to 90, and 51 to 75%, respectively. Early in the outbreak, fir mortality was generally negatively correlated with tree vigor, relative crown position, or diameter at breast height, but in later years, trees were killed irrespective of these factors. Fir mortality was evenly distributed among different sized trees, and 73 to 86% of the trees in each 5 cm diameter at breast height class died. A linear regression equation between dead fir volume and total fir volume explained 89% of the variability in mortality among stands. Percent fir mortality was correlated (r = 0.84) with visual estimates of cumulative defoliation (including all age-classes of foliage) in 1981, but mortality was not correlated with cumulative current annual defoliation or with site characteristics. Using regression equations, fir mortality during this budworm outbreak was predicted to within ±6 m2/ha in 14 of 18 (78%) of the stands, with a relative accuracy of 17.7%.
Lodgepole pine regeneration in an old, self-perpetuating forest in south central Oregon
Authors: Stuart John D. , Agee James K. , Gara Robert I.
Published: October 2008

Historic regeneration patterns and regeneration requirements were investigated in an old, self-regenerating lodgepole pine (Pinusconforta Dougl. ssp. murrayana (Balf.) Critchfield) forest in south central Oregon. The forest was multiaged, with episodic regeneration pulses being correlated with mountain pine beetle (Dendroctonusponderosae Hopk.) outbreaks or fire. The magnitude of a regeneration pulse was a function of disturbance intensity. Tree ring indices show growth declines prior to mountain pine beetle outbreaks. Radial tree growth improved following disturbance. Differences in stand structure among climax lodgepole pine stands in the Rocky Mountains, Sierra Nevada, and south central Oregon were related to disturbance type, frequency, and intensity. Successful lodgepole pine reproduction was limited by soil moisture and partly by microclimate. Shading did not inhibit seedling establishment, but rather provided relief from excessive evapotranspiration, heat, and frost.
The role of climate on present and past vitality of silver fir forests in the Vosges mountains of northeastern France
Authors: Becker Michel
Published: October 2008

A dendroecological study was carried out on 196 sites distributed throughout the whole natural range of silver fir (Abiesalba Miller) in the Vosges mountains of northeastern France. At each site, six dominant trees were bored to the pith. Stand age varied, intentionally, from 40 to 180 years. All tree rings were measured and crossdated; data were then standardized with reference to the mean curve ring width vs. cambial age. The growth indices obtained in this way were studied (setting aside the cambial age) and revealed a great increase in mean vigour from 1830 to 1930–1940 (+70%) and a slight decrease from 1930–1940 to the present (−10%). Using meteorological data from Strasbourg (monthly precipitation and temperature data available from 1881) and a stepwise multiple linear regression, a climatic model was created that explains 79% of the variance. This amount included not only the monthly parameters of years y (year of ring formation) and y − 1 in the model, but also the parameters of years y − 2 toy − 6. Thus, the notion of structural autocorrelation loses much of its credibility in comparison with the notion of climatic aftereffects. The statistical validation of the model distinguishes a calibration period (1881–1960) and a verification period (1961–1983). The model reconstructs the long-term trends satisfactorily, as well as periodic severe growth declines of silver fir in 1917–1923, 1943–1951, and 1976–1983. These phenomena are mainly explained by climatic factors. The possible aggravating role of air pollution is put forward, in particular, the role of the CO2 increases during the last century.
Correlated responses of height increment and components of increment in 2-year-old Douglas-fir
Authors: Kaya Zeki , Campbell R. K. , Adams W. T.
Published: October 2008

The consequences for growth and phenology of early selection for height or its growth components were evaluated in 160 open-pollinated families of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) from southwestern Oregon. Seedlings from two inland and two coastal populations (40 families each) were grown for two growing seasons in a common garden. Predicted response to selection suggests that risk of low juvenile–mature correlation and maladaptation with early selection would be less in the inland than in the coastal region. A phenological event that influences a common growth pattern seems to account for the difference in response. Early bud set in the 1st year was genetically correlated with larger overwintering buds in seedlings from both inland and coastal regions. These larger buds yielded a large increment of predetermined growth in the 2nd year, followed by little or no free growth and early bud set. Seedlings with late bud set in the 1st year had the converse pattern. Inland seedlings set buds much earlier on the average than did coastal seedlings; hence seedlings from the two regions had different growth patterns. Risks that can attend early selection for height generally would be decreased in both regions by selecting for predetermined growth, but several qualifications are discussed.
The effects of fertilization and thinning on wood quality of a 24-year-old Douglas-fir stand
Authors: Jozsa L. A. , Brix H.
Published: October 2008

This report describes the growth and wood density response of a coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand on a poor site to thinning and nitrogen fertilization. The treatment plots were established in 1971 and 1972 at about 24 years of age. The effects of fertilization and thinning were evaluated 12 and 13 years after the initial treatments of the 1972 and 1971 plots, respectively, and 3 years after refertilization of the 1972 plots in 1981. Ring-width and ring-density data were obtained from pith to bark for all trees and were derived from computerized X-ray densitometry. Fertilization reduced ring density at breast height and 25% stem height by an average of 16% for a 3- to 4-year period after treatment, but not thereafter. Reductions in ring density resulted from decreases in the density of early wood and latewood, as well as from decreases in the percent of latewood. Effects were only pronounced in the lower half of the stem. Thinning resulted in a slight ring-density gain in the lower bole and a reduction in the top. The combined treatments had an intermediate effect on ring density. Ring density showed an increasing trend from pith to bark at all heights, except at the 75% height, and a decrease with increasing height in the bole. Fertilization and thinning both increased diameter growth, and their beneficial effects were still evident 13 years after treatments.
Polymorphic height and site index curves for lodgepole pine in Alberta
Authors: Cieszewski C. J. , Bella I. E.
Published: October 2008

This new, biologically based, nonlinear regression model produces polymorphic site index and height curves as a function of prediction age and a height at any age. The curves are constrained to pass through the origin and appropriate heights at any index age. The model was parametrized on 970 stem-analyzed trees and tested on tree measurements from 147 permanent sample plots. Compared with other lodgepole pine (Pinuscontorta var. latifolia Engelm.) height models in Alberta, this model had fewer parameters, yet showed better accuracy and precision than the other models. Above all, the new model provides compatible site index and height estimates, and it can predict height without prior knowledge of site index.
Interspecific pollen–pistil incongruity in Salix
Authors: Mosseler A.
Published: October 2008

Pollination barriers that restrict hybridization between six Salix spp. (S. amygdaloides Anderss., S. exigua Nutt., and S.lucida Muhl., of subgenus Salix, and S. discolor Muhl., S. eriocephala Michx., and S. petiolaris Smith of subgenus Vetrix) and that are sympatric over much of their ranges in central North America were investigated through artificial cross pollination. Foreign species' pollen generally adhered to and germinated on the stigma. Pollen–pistil incongruity was most often expressed as reduced pollen tube growth rate, but the degree of incongruity was highly variable within and between different species combinations. Morphological abnormalities such as swollen, coiled, and undirected pollen tube growth were observed in some crosses but were not common. The stigma of S. eriocephala Michx. exhibited a particularly strong and characteristic inhibition of all foreign species' pollen tube growth. Despite the presence of some form of pollen–pistil incongruity in most interspecific crosses, pollen tube penetration of the ovule micropyle (fertilization) was successful in several species combinations.
A test of a nonparametric distance-based estimator for seedling density
Authors: Fairweather Stephen E. , Amrhein John F.
Published: October 2008

Two sampling methods were used to estimate the number of seedlings per acre on a 15-month-old clear-cut in central Pennsylvania. The seedling population was very dense, and the spatial distribution was highly aggregated. The first method used distance sampling and a nonparametric estimator, and the second method used conventional quadrat sampling (milacre plots (1 milacre = 0.0004 ha)). Based on simulated sampling trials on the mapped seedling population, the distance sampling estimator was severely biased, whereas quadrat sampling yielded unbiased estimates of density.
Tree-ring analysis as an aid to evaluating the effects of pollution on tree growth
Authors: Innes J. L. , Cook E. R.
Published: October 2008

Tree-ring analysis has frequently been used to assess the impact of pollution on tree growth around point sources. Its use in studies of the impact of air pollutants operating on a regional scale is more controversial. A variety of analysis procedures is available, and these should be carefully selected in relation to the problem under investigation. To assess the impact of regional air pollutants, nonstationary response functions, as developed using the Kalman filter technique, offer considerable potential. In the current spruce–fir debate in North America, tree-ring analysis has indicated that the current declines are unprecedented within the last 200 years in terms of the duration of depressed growth or the extent to which growth has been depressed. It has indicated that red spruce (Picearubens Sarg.) is particularly susceptible to certain climatic conditions (higher than average July and August temperatures and lower than average November and December temperatures). Since the onset of the decline, the growth of red spruce has been less than predicted from climatic factors, suggesting that the importance of some other effect on growth has increased or that there has been a change in the climatic factors influencing growth. In Europe, tree-ring analysis has helped to quantify the relationship between crown density and increment.
Engelmann × Sitka spruce hybrids in central British Columbia
Authors: Kiss G. K.
Published: October 2008

Several crosses of Engelmann × Engelmann and Engelmann × Sitka spruce (one parent) were studied. Average crossability of the latter was 24.5%. Average heights of the pure Engelmann and the hybrid spruce were 361.6 and 183.6 cm, respectively, at plantation age 13 (16 years from seed). The difference in height appeared to be the result of repeated winter kill of large proportions of the previous summer's growth. Age to age correlations for total tree heights at 3–7 and 7–13 years old were highly significant. Based on these results, Engelmann × Sitka spruce hybrids are not recommended for reforestation purposes in the north-central interior of British Columbia. However, there are indications that preselecting better genotypes may improve the performance of the resulting hybrids; thus, further research in this direction is warranted.
Height and crown width related to diameter for open-grown western hemlock and Sitka spruce
Authors: Farr Wilbur A. , DeMars Donald J. , Dealy J. Edward
Published: October 2008

Data from 157 open-grown Sitka spruce (Piceasitchensis (Bong.) Carr.) and 102 western hemlock (Tsugaheterophylla (Raf.) Sarg.) at two locations in coastal Alaska and from 69 Sitka spruce on the Queen Charlotte Islands in British Columbia were used to develop height–diameter and crown width–diameter equations. Height–diameter relations for Sitka spruce were significantly different among all locations. Crown width–diameter relations were not significantly different. Common equations were fit to the spruce data and to the spruce and hemlock data independent of location and site index along the coast.
Cone depredations by the red squirrel in black spruce stands in Newfoundland: implications for commercial cone collection
Authors: West R. J.
Published: October 2008

The proportions of black spruce (Piceamariana (Mill.) B.S.P.) cones per tree that were removed by red squirrels, Tamiasciurushudsonicus (Erxleben), in years with small cone crops (1985–1987) ranged from 15 to 64% by the end of August and from 64 to 96% by the beginning of October, whereas in a year with a good cone crop (1988), less than 1% of cones had been taken by October. To minimize depredation of cones by squirrels, commercial cone collecting is recommended for a short period beginning in late August during years with small cone crops, whereas a lengthy period of commercial cone collection beginning in late August is suggested for years with large cone crops.
Early selection in tree breeding: principles for applying index selection and inferring input parameters
Authors: Burdon R. D.
Published: October 2008

not available
A comparative study of shoot and root development of interior and coastal Douglas-fir seedlings
Authors: Fielder Peter , Owens John N.
Published: October 2008

not available
Treatments influencing susceptibility of Nothofaguscunninghamii to the ambrosia beetle Platypussubgranosus in Australia
Authors: Kile G.A. , Elliott H.J. , Candy S.G. , Hall M.F.
Published: October 2008

Of treatments imposed to stress Nothofaguscunninghamii (Hook.) Oerst. trees, only infection by the vascular stain pathogen Chalaraaustralis Walker & Kile caused intensive and sustained attack by the ambrosia beetle Platypussubgranosus Schedl. Other treatments that damaged stems or led to tree death resulted in some P. subgranosus attack soon after treatment or at death, but effects were generally small compared with those of C. australis infection. The number of tunnels initiated on stems by the beetle was correlated with the number of beetles caught on adhesive traps on the same trees. Platypussubgranosus attack on inoculated trees was nonrandom and associated with the presence of C. australis in the underlying wood. Injection of trees with isobutyl acetate, the major volatile metabolite produced by the fungus invitro, did not increase their attractiveness to P. subgranosus. Wounded Atherospermamoschatum Labill. were also attacked by P. subgranosus.
Development of a well-behaved site index equation: jack pine in north central Ontario
Authors: Goelz J.C.G. , Burk T.E.
Published: October 2008

A base-age invariant site index equation for jack pine based on the Chapman–Richards function was produced that satisfied nine criteria of preferred behavior for site index equations. A difference form of the Chapman–Richards equation produced the best behavior; height equalled site index at base age, and the shape of the curves reflected the data. The data structure used to fit the difference equation was all possible differences rather than the conventional nonoverlapping sequential intervals because this improved the behavior of the model. Height-prediction equations typically use height at base age (site index) as a predictor variable. As site index is measured with error, the equation will be biased. This bias will be evident in the predicted height at base age and in the shape of the curves. Base-age invariant equations predict height and site index with the same equation and thus diminish the effect of stochastic predictor variables. The equation performed comparably to a previously published equation with a specific base age of 50 years.
Delineation of climatic regions in Maine
Authors: Briggs R.D. , Lemin Jr. R.C.
Published: October 2008

As part of a project to develop a productivity-oriented site classification system for spruce and fir in Maine, multivariate analyses of meteorological data were used to partition the state into homogeneous climatic zones. Data were obtained for 63 weather stations reporting both temperature and precipitation in Maine during the period 1954–1983. Monthly means were computed for each variable over the period of record and summarized by four 3-month seasons. Eighty-two percent of the variation in the 37 variables was accounted for by the first three principal components. Cluster analysis identified eight homogeneous groups of weather stations. Results from the principal components analysis were spatially extrapolated across the state using stepwise regression to define the relationship between the first two principal components and the location variables latitude, longitude, and elevation. Principal component scores were predicted across the state along a grid composed of township line intersections. The Triangulated Irregular Network of ARCINFO, a geographic information system software package, was used to spatially summarize the predicted component scores into climagraphic maps. The combined results from cluster analysis and spatial extrapolation of the principal components analysis suggested the presence of four broad climatic regions, which were further subdivided into nine climatic zones. Overlap among the four regions and nine zones was evaluated with a jackknifed classification of a linear discriminant function. Ninety-four percent of the weather stations were correctly classified by climatic region, whereas 76% were correctly classified by climatic zone. The high degree of correspondence between climatic zones and biophysical regions reinforced results of the multivariate analyses.
Impact analysis for a jack pine budworm infestation in Ontario
Authors: Gross Henry L.
Published: October 2008

Four jack pine (Pinusbanksiana Lamb.) stands in northeastern Ontario that experienced varying levels of defoliation by the jack pine budworm (Choristoneurapinuspinus Free.) from 1984 to 1986 were studied to develop methods for estimating defoliation impact. Annual growth was determined by complete stem analysis. Growth estimators identified by regression indicated significant growth loss from 1985 to 1988. The loss was greatest in 1986, after intense defoliation in 1985. Losses, compared with growth for the 5 years before infestation, ranged from 56 to 75% in 1986, 28 to 50% in 1987, and 15 to 31% in 1988 for dominant and codominant trees. Growth was unaffected in a stand that experienced negligible defoliation. Mortality caused by defoliation was <1% for dominant and codominant trees, ranged from 9 to 60% for intermediate and suppressed trees in defoliated stands, and was 13% in the stand with negligible defoliation. This indicated that other factors, not just defoliation, were responsible for mortality of suppressed and intermediate trees. Dead tops were common for suppressed and intermediate jack pine in all defoliated stands, and for dominant and codominant trees in the two semimature defoliated stands. Growth loss was greatest in parts of the bole adjacent to defoliated crown. Regression identified estimators of the bias in estimates based on growth relationships for DBH and height rather than on the more sensitive stem analysis procedure. Models identified within-stand bias satisfactorily; however, no composite model was identified for all stands combined. The magnitude of estimation errors due to bias is discussed.
Genetic variation and productivity of Populustrichocarpa and its hybrids. V. The influence of ramet position on 3-year growth variables
Authors: Dunlap J.M. , Heilman P.E. , Stettler R.F.
Published: October 2008

A 3-year study was conducted on the effects of different stem positions (from which cuttings were taken on a stool-bed ortet) on sprouting characteristics and stem growth of Populustrichocarpa Torr. & Gray. In 1986 ramets were collected from five stem positions, evenly distributed from the base to the tip, on three stool-bed ortets of each of 30 clones representing three river valleys in western Washington. Each set of five was planted at 1.22-m spacing in one of three adjacent blocks in an experimental field in Puyallup, Washington. First-year results showed that cuttings from the upper two positions tended to leaf out earlier and develop a single rather than multiple stem as compared with those from the lower positions. Analyses of variance of growth traits showed significant position, position–river, and position–clone within river interaction effects. Positional effects on sprouting and growth were strong primarily for material from the Dungeness River. At the end of the 3rd year, the largest Dungeness ramets (from position 2 near the top) averaged 860 cm in height and 7.3 cm in diameter, whereas the smallest (from position 4) averaged 753 and 5.8 cm, respectively. By this time, it appeared that the shorter trees had begun to suffer from competition associated with crown closure. Thus, the impact of competition in a tightly spaced, multiclonal plantation can influence the ultimate growth and survival of different clones and thereby bias a genetic evaluation.
Comparison of methods for estimating soil nitrogen transformations in adjacent conifer and alder–conifer forests
Authors: Binkley Dan , Bell Randy , Sollins Phillip
Published: October 2008

Nitrogen transformations were examined in two pairs of adjacent, 55-year-old forests dominated by conifers (primarily Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco)) and by conifers and nitrogen-fixing red alder (Alnusrubra Bong.). Nitrogen availability was examined in aerobic and anaerobic incubations in the laboratory, and with resin-core and buried-bag incubations in the field. Rates of nitrogen mineralization and immobilization were examined in the field incubations using [15N]ammonium. Net nitrogen mineralization in a year-long series of resin-core incubations of forest floor plus 0–0.15 m depth soil was about 9 kmol•ha−1•year−1 for the two alder–conifer stands, but almost nil in the conifer stand at the low-productivity Wind River site, and 2.1 kmol•ha−1•year−1 in the conifer stand at the high-productivity Cascade Head site. The 15N pool dilution experiment showed that buried-bag incubations demonstrated more differences among stands than did resin cores; resin cores typically gave greater rates than buried bags. Previous estimates of nitrogen budgets were coupled with net mineralization estimates to examine how well the estimated fluxes balanced at an ecosystem scale. This tabulation of the complete nitrogen cycles showed substantial discrepancies, prompting caution in interpretation of some of the differences among the stands.
Red spruce soil solution chemistry and root distribution across a cloud water deposition gradient
Authors: Joslin J.D. , Wolfe M.H.
Published: October 2008

The decline of red spruce (Picearubens Sarg.) at high elevations in eastern North America has been linked in time and space with exposure to acidic cloud water. To investigate the belowground effects of a cloud water deposition gradient between two mature red spruce stands on the summit of Whitetop Mountain, Virginia, the chemistries of precipitation, throughfall, and soil solution were monitored over a 2-year period, and fine-root distributions were characterized. Deposition of water, sulfate, nitrate, and ammonium in throughfall and stemflow was from 15 to 55% greater at the site with greater exposure to cloud water deposition (high cloud site), depending upon the particular ion and year. Soil solution nitrate concentrations were highly variable over time, and base cation, Al, and H ion concentrations were highly correlated with nitrate in both organic and mineral horizons at both sites. Soil solution nitrate, base cation, Al, and H ion concentrations were two to six times greater during periods of low soil moisture in the summer–autumn of 1987 and 1988 than during the remainder of the study period. In the mineral soil solutions, the high cloud site had significantly higher (p < 0.001) concentrations of nitrate and Al, and significantly lower (p < 0.05) Ca:Al and Mg:Al ratios. The high cloud stand also had shallower root systems, with fine-root biomass less than 40% of that of the low cloud stand (p < 0.05) at all depths greater than 18 cm. Soil solutions collected from below 15 cm at the high cloud site had a mean Ca:Al ratio less than 0.5 and Al concentrations that during dry periods, frequently approached or exceeded the literature values for the toxicity threshold for red spruce root growth. Restricted root development in the high cloud stand was apparently the result of this unfavorable chemical environment.
Prevalence of individual-tree growth decline in red spruce populations of the southern Appalachian Mountains
Authors: LeBlanc David C. , Nicholas N.S. , Zedaker S.M.
Published: October 2008

The prevalence of individual-tree growth decline was determined for red spruce (Picearubens Sarg.) populations at three locations in the southern Appalachians: Mount Rogers National Recreation Area, the Black Mountains, and Great Smoky Mountain National Park. An index of annual stemwood volume increment (AVI) was computed from dendrochronological data and a site-specific DBH–height regression equation. Individual-tree AVI time series were analyzed to identify changes in 20-year periodic mean AVI and AVI trend. The proportion of red spruce that exhibited decreasing mean AVI or negative AVI trend was determined for the most recent 20-year period, and this was compared with the estimated historical prevalence of these indications of growth decline. Also, the prevalence of growth decline was compared among subpopulations that differed with regard to various tree, stand, and site characteristics. Of 263 red spruce sampled, 25% exhibited a decrease in mean AVI during the period 1967–1986, 8% exhibited a negative AVI trend without a reduction in mean AVI, and 17% exhibited a reduction in the slope of the AVI curve. The proportion of trees that exhibited decreasing or slowed growth after 1967 was substantially greater among trees growing at 1980 m than in populations at lower elevations; no relationship was found between elevation and growth decline below 1980 m. No difference was found in prevalence of growth decline between subpopulations that differed with regard to age, DBH, competitive status, stand density, slope aspect, or site exposure. The prevalence of individual-tree growth decline for the most recent 20-year period did not exceed estimated levels for historical periods of decline in the Great Smoky Mountains population.
Anaerobically mineralizable soil N as a predictor of growth response to fertilization in lodgepole pine
Authors: Weetman G.F. , Prescott C E. , Fournier R.M.
Published: October 2008

The relationship between the amount of mineralizable N in mineral soil and the basal area response of trees to N fertilization was examined in 24 stands of lodgepole pine (Pinuscontorta var. latifolia Engelm.) in interior British Columbia. Plots received a single application of either NH4NO3 or urea between 1980 and 1983. Increment cores taken from trees on fertilized and control plots 4 years after fertilization were used to estimate basal area response of fertilized trees relative to controls. Amounts of N mineralized during a 1-week anaerobic incubation of mineral soil from control plots at each site were used as an estimate of N availability in each stand. The relationship between N availability and growth response of trees was weak, except that stands with mineralizable soil N greater than 40 ppm were not responsive to fertilization. Measurement of mineralizable soil N might be useful prior to screening trials to eliminate stands with very high levels of available N.
Inhibition of heme oxygenase activity in newborn mice by azalanstat
Authors: Morisawa Takeshi , Wong Ronald J. , Bhutani Vinod K. , Vreman Hendrik J. , Stevenson David K.
Published: October 2008

Inhibition of heme oxygenase (HO), the rate-limiting enzyme in heme catabolism, may be an ideal strategy for preventing neonatal jaundice. Although natural and synthetic heme analogs, called metalloporphyrins (Mps), have been extensively investigated for this purpose, some Mps are phototoxic, affect the activity of other enzymes, or induce HO-1 transcription—properties that may limit their clinical use. Another class of compounds, imidazole–dioxolanes, has been shown to selectively inhibit the inducible isozyme HO-1. Therefore, we investigated the efficacy of azalanstat (AZA), an imidazole–dioxolane, towards inhibiting HO activity in 7-day-old mice. We found that a single dose of AZA at 500 µmol·kg–1body mass (BM) administered i.p. significantly inhibited HO activity and reduced in vivo bilirubin production. In the spleen, HO inhibition (>50%) was observed within 0.25–3 h after administration. After 24 h, however, spleen HO activity, HO-1 protein, and HO-1 mRNA levels significantly increased 1.2-, 2.4-, and 4.0-fold, respectively. We conclude that AZA effectively inhibits in vivo HO activity only at a high dose and that it also induces spleen HO-1 gene transcription. Therefore, other imidazole–dioxolanes should be evaluated to determine whether they are more potent than AZA for use in treating neonatal jaundice.
Effect of crude sulphated polysaccharide from brown algae against acetaminophen-induced toxicity in rats
Authors: Raghavendran Hanumantha Rao Balaji , Srinivasan Periasamy
Published: October 2008

This study was conducted to examine the protective role of crude polysaccharide from brown seaweed Sargassum polycystum against acetaminophen-induced abnormality in blood glucose, serum albumin/globulin ratio, and liver glycogen, lactate, and pyruvate. Liver and renal tissue histology was performed to confirm the efficacy of Sargassum polysaccharide. A toxic dose of acetaminophen (800 mg/kg body weight intraperitoneally) induced severe abnormality in all basic parameters with apparent toxicity in liver (enlargement of hepatocytes, loss of cytoplasmic content with disruption in the hepatic plates and sinusoidal dilation) and renal tissue (glomerular damage with congestion of tubules). The isolated liver cells were stained with acridine orange and examined under fluorescence microscope, which revealed that the acetaminophen induced significant damage. In contrast, the rats pretreated with Sargassum polysaccharide (200 mg/kg body weight) daily for 3 weeks did not show liver and renal tissue with these severe aberrations induced by acetaminophen. Histology results were also consistent with analyzed basic biochemical parameters, which confirmed the effectiveness of the crude polysaccharide against acetaminophen-induced abnormality in rats.