bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization of Lactoferrin-Bound and Transferrin-Bound Iron by
Campylobacter jejuni
Authors: Miller Claire E. , Rock Jonathan D. , Ridley Kristian A. , Williams Peter H. , Ketley Julian M.
Published: January 2008

Campylobacter jejuni
NCTC 11168 was capable of growth to levels comparable with FeSO
4
in defined iron-limited medium (minimal essential medium alpha [MEMα]) containing ferrilactoferrin, ferritransferrin, or ferri-ovotransferrin. Iron was internalized in a contact-dependent manner, with 94% of cell-associated radioactivity from either
55
Fe-loaded transferrin or lactoferrin associated with the soluble cell fraction. Partitioning the iron source away from bacteria significantly decreased cellular growth. Excess cold transferrin or lactoferrin in cultures containing
55
Fe-loaded transferrin or lactoferrin resulted in reduced levels of
55
Fe uptake. Growth of
C. jejuni
in the presence of ferri- and an excess of apoprotein reduced overall levels of growth. Following incubation of cells in the presence of ferrilactoferrin, lactoferrin became associated with the cell surface; binding levels were higher after growth under iron limitation. A strain carrying a mutation in the cj0178 gene from the iron uptake system Cj0173c-Cj0178 demonstrated significantly reduced growth promotion in the presence of ferrilactoferrin in MEMα compared to wild type but was not affected in the presence of heme. Moreover, this mutant acquired less
55
Fe than wild type when incubated with
55
Fe-loaded protein and bound less lactoferrin. Complementation restored the wild-type phenotype when cells were grown with ferrilactoferrin. A mutant in the ABC transporter system permease gene (cj0174c) showed a small but significant growth reduction. The cj0176c-cj0177 intergenic region contains two separate Fur-regulated iron-repressible promoters. This is the first demonstration that
C. jejuni
is capable of acquiring iron from members of the transferrin protein family, and our data indicate a role for Cj0178 in this process.
Nondecarboxylating and Decarboxylating Isocitrate Dehydrogenases: Oxalosuccinate Reductase as an Ancestral Form of Isocitrate Dehydrogenase
Authors: Aoshima Miho , Igarashi Yasuo
Published: January 2008

Isocitrate dehydrogenase (ICDH) fromHydrogenobacter thermophiluscatalyzes the reduction of oxalosuccinate, which corresponds to the second step of the reductive carboxylation of 2-oxoglutarate in the reductive tricarboxylic acid cycle. In this study, the oxidation reaction catalyzed byH. thermophilusICDH was kinetically analyzed. As a result, a rapid equilibrium random-order mechanism was suggested. The affinities of both substrates (isocitrate and NAD+) toward the enzyme were extremely low compared to other known ICDHs. The binding activities of isocitrate and NAD+were not independent; rather, the binding of one substrate considerably promoted the binding of the other. A product inhibition assay demonstrated that NADH is a potent inhibitor, although 2-oxoglutarate did not exhibit an inhibitory effect. Further chromatographic analysis demonstrated that oxalosuccinate, rather than 2-oxoglutarate, is the reaction product. Thus, it was shown thatH. thermophilusICDH is a nondecarboxylating ICDH that catalyzes the conversion between isocitrate and oxalosuccinate by oxidation and reduction. This nondecarboxylating ICDH is distinct from well-known decarboxylating ICDHs and should be categorized as a new enzyme. Oxalosuccinate-reducing enzyme may be the ancestral form of ICDH, which evolved to the extant isocitrate oxidative decarboxylating enzyme by acquiring higher substrate affinities.
Global Responses of
Methanococcus maripaludis
to Specific Nutrient Limitations and Growth Rate
Authors: Hendrickson Erik L. , Liu Yuchen , Rosas-Sandoval Guillermina , Porat Iris , Söll Dieter , Whitman William B. , Leigh John A.
Published: January 2008

Continuous culture, transcriptome arrays, and measurements of cellular amino acid pools and tRNA charging levels were used to determine the response of
Methanococcus maripaludis
to leucine limitation. For comparison, the responses to phosphate and H
2
limitations were measured as well. In addition, the effect of growth rate was determined. Leucine limitation resulted in a broad response. tRNA
Leu
charging decreased, but only small increases in mRNA were seen for amino acid biosynthesis genes. However, the cellular levels of free isoleucine and valine showed significant increases, indicating a coordinate regulation of branched-chain amino acids at a post-mRNA level. Leucine limitation also resulted in increased mRNA abundance for ribosomal protein genes, increased rRNA abundance, and decreased mRNA abundance for genes of methanogenesis. In contrast, phosphate limitation induced a specific response, a marked increase in mRNA levels for a phosphate transporter. Some mRNA levels responded to more than one factor; for example, transcripts for flagellum synthesis genes decreased under conditions of leucine limitation and increased under H
2
limitation. Increased growth rate resulted in increased mRNA levels for ribosomal protein genes, increased rRNA abundance, and increased mRNA for a gene encoding an S-layer protein.
Collegiate rugby union injury patterns in New England: A prospective cohort study
Authors: Kerr Hamish A. , Curtis Christine M. , Micheli Lyle J. , Kocher Mininder S. , Zurakowski David , Brooks John H.M. , Kemp Simon P.T.
Published: January 2008

Objective:Establish injury profile of collegiate rugby union in the U.S.A.

Design/setting:31 men's and 38 women's collegiate rugby union teams prospectively recorded injuries during games and practice during 2005-06. 3 teams withdrew prior to data collection. An injury was defined as;

1. Occurring in an organized intercollegiate game or practice; and

2. Requiring medical attention during or after the game or practice, or

3. Resulting in any restriction of the athletes' participation for ≥1 day(s) beyond the day of injury, or in a dental injury. Main Outcome measurements: A total of 847 injuries (men:447; women:400) during 48,026 practice (men:24,280; women:23,746) and 25,808 game (men:13,943; women:11,865) exposures were recorded.

Results:During games, injury rates of 22.5(95 per cent confidence interval: 20.2-25.0) and 22.7(20.2-25.5)/1,000 game athletic exposures (GAE) or 16.9 (15.1-18.9) and 17.1(15.1-19.1)/1,000 player game-hours (PGH) were recorded (men; women). Over half of all match injuries were of major severity (> 7 days absence) (men: 56%; women: 51%) and the tackle was the game event most associated with injury (men: 48%; women: 53%).

Conclusions:Collegiate game injury rates for rugby were lower than rates recorded previously in men's professional club and international rugby and lower than reported by the National Collegiate Athletic Association Injury Surveillance System (N.C.A.A. I.S.S.) for American football but similar to rates reported for men's and women's soccer in 2005-06.
Effects of left- or right-hand preference on the success of boxers in Turkey
Authors: Gursoy R
Published: January 2008

Objective:

The purpose of the present study was to evaluate the role of left- or right-handedness on the success of the boxer.

Methods:

The study was based on a sample of 22 active, semi-professional or amateur men boxers attending National Road Sport Men Boxing Club in Erzurum, Turkey. The boxers had been actively boxing for 4–15 years (mean 9.87), were aged 17–46 years (mean 32.25), and weighed 65–101 kg (mean 81.06). They were divided into two groups according to the research protocol (left- and right-handed boxers). The status of left- or right-handedness of the boxer included in the research was determined using the Oldfield (Edinburgh Handedness Inventory) Index. Then the boxers were categorised into two groups (win and defeat). Success rates in both groups were expressed in percentages. The data obtained from both of the groups were compared statistically by means of significance test between proportions (t test).

Results:

Left-handed boxers had been involved in 75–800 fights (mean 120.6), with 5–79 lost (mean 19.32). A similar evaluation was made for the right-handed boxers. The right-handed boxers had been involved in 50–820 fights (mean 127. 8), with 23–78 lost (mean 42.25). Left-handed boxers were found to be more successful than right-handed ones. The difference between them was found to be significant (p<0.01).

Conclusions:

It was concluded that left-handed people should never be forced to convert to right-handedness; instead they should be supported both verbally and in terms of equipment and they should be motivated, because the data obtained proved that left-handedness means success, especially in boxing.
Determinants of fast marathon performance: low basal sympathetic drive, enhanced postcompetition vasodilatation and preserved cardiac performance after competition
Authors: Gratze G , Mayer H , Luft F C , Skrabal F
Published: January 2008

Objective:

To test the hypothesis that enhanced postexercise vasodilatation is related to sympathetic drive to resistance vessels and to fast marathon performance.

Design:

Prospective field study before and after running a marathon.

Participants:

51 healthy amateur runners who volunteered to participate. The fastest competitor finished fourth, the slowest 1290th out of 1324 participants.

Interventions:

None.

Main outcome measurements:

Competition time, beat-to-beat blood pressure by the vascular unloading technique, oscillometric blood pressure, beat-to-beat stroke volume by impedance cardiography, total peripheral resistance changes calculated from blood pressure and stroke volume changes, sympathetic modulation of vasomotor tone and parasympathetic modulation of sinus node function by spectral analysis of blood pressure and heart rate variability, baroreceptor reflex sensitivity by the sequence method.

Results:

Slow performers, in contrast to fast performers, exhibited a higher 0.1 Hz band of diastolic blood pressure variability before the competition (0.1 Hz BPV) (40.0 (SD 2.39) vs 54.9 (2.47), p<0.001), diminished vasodilatation (−11.3 (4.78) vs −29.4 (3.23), p<0.01) and a decrease in stroke index (−14.9 (3.55) vs +0.9 (3.37), p<0.001) in response to the race. Single and multiple regression analyses further corroborated the findings.

Conclusions:

Fast performance in the marathon is associated with low sympathetic modulation of vasomotor tone, maintained stroke index postcompetition and enhanced exercise-induced vasodilatation. We postulate that maintaining a low level of sympathetic modulation to resistance vessels during the course of training may indicate its appropriateness, thus enabling fast performance by optimal postexercise vasodilatation and by prevention of postcompetition cardiac dysfunction. This will have to be tested in future longitudinal studies.
Comparison between various indices of exposure to traffic-related air pollution and their impact on respiratory health in adults
Authors: Cesaroni G , Badaloni C , Porta D , Forastiere F , Perucci C A
Published: January 2008

Objective:

To evaluate the association of different indices of traffic-related air pollution (self-report of traffic intensity, distance from busy roads from geographical information system (GIS), area-based emissions of particulate matter (PM), and estimated concentrations of nitrogen dioxide (NO2) from a land-use regression model) with respiratory health in adults.

Methods:

A sample of 9488 25–59-year-old Rome residents completed a self-administered questionnaire on respiratory health and various risk factors, including education, occupation, housing conditions, smoking, and traffic intensity in their area of residence. The study used GIS to calculate the distance between their home address and the closest high-traffic road. For each subject, PM emissions in the area of residence as well as estimated NO2concentrations as assessed by a land-use regression model (R2value = 0.69), were available. Generalised estimating equations (GEE) were used to analyse the association between air pollution measures and prevalence of “ever” chronic bronchitis, asthma, and rhinitis taking into account the effects of age, gender, education, smoking habits, socioeconomic position, and the correlation of variables for members of the same family.

Results:

Three hundred and ninety seven subjects (4% of the study population) reported chronic bronchitis, 472 (5%) asthma, and 1227 (13%) rhinitis. Fifteen per cent of subjects reported living in high traffic areas, 11% lived within 50 m of a high traffic road, and 28% in areas with estimated NO2greater than 50 μg/m3. Prevalence of asthma was associated only with self-reported traffic intensity whereas no association was found for the other more objective indices. Rhinitis, on the other hand, was strongly associated with all traffic-related indicators (eg, OR = 1.13, 95% CI: 1.04 to 1.22 for 10 μg/m3NO2), especially among non-smokers.

Conclusions:

Indices of exposure to traffic-related air pollution are consistently associated with an increased risk of rhinitis in adults, especially among non-smokers. The results for asthma are weak, possibly due to ascertainment problems.
Increased expression of placenta growth factor in COPD
Authors: Cheng S-L , Wang H-C , Yu C-J , Yang P-C
Published: January 2008

Background:

Vascular endothelial growth factor (VEGF) and its receptor may have an important role in the pathogenesis of emphysema. The effect of another angiogenic factor, placenta growth factor (PlGF), in chronic obstructive pulmonary disease (COPD) is unknown.

Methods:

The serum levels of VEGF and PlGF in patients with COPD (n = 184), smokers (n = 212) and non-smokers (n = 159) and the bronchoalveolar lavage (BAL) fluid levels of VEGF and PlGF in another group (20 patients with COPD, 18 controls) were measured. In vitro cell culture experiments were performed to investigate the effect of PlGF on VEGF.

Results:

The mean (SE) serum levels of PlGF were significantly higher in patients with COPD than in controls (27.1 (7.4) pg/ml vs 12.3 (5.1) pg/ml in smokers and 10.8 (6.3) pg/ml in non-smokers, p = 0.005). The levels of PlGF in BAL fluid were also significantly higher in patients with COPD than in controls (45.7 (12.3) pg/ml vs 23.9 (7.6) pg/ml, p = 0.005), associated with an increase in the cytokines tumour necrosis factor-α (TNF-α) and interleukin-8 (IL-8). In patients with COPD the levels of PlGF correlated inversely with forced expiratory volume in 1 s (FEV1) in serum (r = −0.59, p = 0.002) and in BAL fluid (r = −0.51, p = 0.001). While the serum levels of VEGF were the same in patients with COPD and controls, the BAL fluid levels were significantly lower in patients with COPD than in controls (127.5 (30.1) pg/ml vs 237.8 (36.1) pg/ml, p = 0.002). In cultured bronchial epithelial cells, proinflammatory cytokines induced an increase in the protein expression of both PlGF and VEGF. Continuous concomitant treatment with PlGF, TNF-α and IL-8 stimulation reduced VEGF expression and induced cell death. This phenomenon was suppressed by VEGF receptor inhibitor (CBO-P11).

Conclusions:

The serum and BAL fluid levels of PlGF are increased in patients with COPD and are inversely correlated with FEV1. Concomitant treatment with PlGF, TNF-α and IL-8 causes detrimental effects on airway epithelial cells. These data suggest that bronchial epithelial cells can express PlGF, which may contribute to the pathogenesis of COPD.
Selection for biomass production based on respiration parameters in eucalypts: effects of origin and growth climates on growth rates
Authors: Anekonda Thimmappa S. , Criddle Richard S. , Hansen Lee D. , Bacca Mike
Published: January 2008

Seventeen Eucalyptus species and 30 rapid-growing Eucalyptuscamaldulensis trees (referred to as plus trees), growing in a plantation were studied to examine relationships among measured plant growth and respiratory parameters, geographical origins, and growth climate. The respiratory parameters measured at two different temperatures by isothermal calorimetry were metabolic heat rate, rate of CO2 production, and the ratio of heat rate to CO2 rate. Metabolic heat rate was also measured as a continuous function of temperature by differential scanning calorimetry in the range of 10 to 40 °C. Tree growth was measured as rates of height and stem volume growth. The values of respiratory and growth variables of Eucalyptus species are significantly correlated with latitude and altitude of origin of their seed sources. The maximum metabolic heat rate, the temperature of the maximum heat rate, the temperature coefficients of metabolic rate, and the temperatures at which the slopes of Arrhenius plots change are all genetically determined parameters that vary both within and among species. Measurement of growth rate–respiration rate–temperature relationships guide understanding of why relative growth rates of Eucalyptus species and individual genotypes differ with climate, making it possible to identify genotypes best suited for rapid growth in different climates. The temperature dependence of respiration rates is an important factor determining relative growth rates of eucalypts in different climates. To achieve optimum biomass production the temperature dependence of individual plants must be matched to growth climate.
Effect of two commercial formulations of Bacillusthuringiensis suhsp. kurstaki on the forest earthworm Dendrobaenaoctaedra
Authors: Addison J.A. , Holmes S.B.
Published: January 2008

The effects of Dipel®8L and Dipel®8AF (two formulations of Bacillusthuringiensis subsp. kurstaki (B.t.k.)) on the survival, growth, and reproduction of the forest earthworm Dendrobaenaoctaedra (Sav.) were studied in the laboratory using simple soil–litter microcosms. Dendrobaenaoctaedra was not adversely affected by an unformulated preparation of B.t.k. or by the aqueous formulation (Dipel®8AF) even at doses representing 1000× the expected environmental concentration (EEC). However, survival, growth, and cocoon production were significantly reduced in the presence of Dipel®8L at 1000× EEC, which is the level recommended for Tier I testing for environmental effects according to the Canadian guidelines for registration of naturally occurring microbial pest control agents. Further tests indicated that the toxic component of the Dipel®8L was the oil-based formulation blank. No significant deleterious effects on survival, growth, or reproduction were observed in microcosms sprayed with Dipel®8L at the EEC, 10× EEC, or 100× EEC. There was no evidence of a synergistic reaction between oil-based formulation ingredients and B.t.k., which would act to increase the susceptibility of D. octaedra to the bacterium.
Ozone effects on nutrient resorption in loblolly pine
Authors: Baker Timothy R. , Allen H. Lee
Published: January 2008

A three-year study on the effects of chronic exposure to elevated ozone on loblolly pine (Pinustaeda L.) was conducted at a site in the Piedmont of North Carolina. Open-top chambers were used to control six levels of ozone, from 0.50 times ambient to 3.0 times ambient ozone concentration, on two open-pollinated families with suspected differences in sensitivity to ozone. Nutrient concentrations and contents were measured in fascicles obtained before and after abscission. Ozone strongly accelerated fascicle abscission and also tended to increase most nutrient concentrations in both pre- and post-abscission fascicles. There was, however, no significant impact of the ozone treatment on the amounts of nutrients resorbed during abscission. These data suggest that nutrient resorption associated with elevated ozone exposure followed a pattern more closely approximating accelerated senescence rather than premature abscission per se. The two open-pollinated families did not differ in nutrient resorption but did have isolated differences in the pre- and post-abscission fascicle concentrations.
Use of a Pilodyn for the indirect selection of basic density in Eucalyptusnitens
Authors: Greaves B.L. , Borralho N.M.G. , Raymond C.A. , Farrington A.
Published: January 2008

Six hundred 7-year-old Eucalyptusnitens (Dean & Maid.) trees from 50 open-pollinated families were measured for wood density and Pilodyn penetration across two contrasting sites in eastern Victoria, Australia. Eight Pilodyn observations, two from each of four aspects, were made at a height of 1.3 m. Density was measured on whole disks cut from 1.3 m. Heritability of Pilodyn penetration and disk density at 1.3 m were 0.60 and 0.73, respectively. Phenotypic and genetic correlations between Pilodyn penetration and density at 1.3 m were −0.59 and −0.92, respectively. The high repeatability of Pilodyn penetration (0.90) suggests that only two observations per tree would be required for indirect selection of density. Direct index selection for density gave an expected 13% gain (assuming a selection intensity of 1%), compared with a 11% gain by using indirect Pilodyn selection, a selection efficiency of 84%. However, Pilodyn sampling is faster, cheaper, and not destructive, thus resulting in overall higher expected gains for selection of trees or culling of seedling seed orchards in comparison with the more destructive direct assessment of density.
Characterization of globoids and iron-rich particles in cotyledons of Pinusbanksiana seeds and seedlings
Authors: Pittermann Jarmila , West Marcia , Lott John N.A.
Published: January 2008

The cotyledons of Pinusbanksiana Lamb, from dry seeds and seedlings were studied for differences in the elements present in globoids. Globoids are mineral nutrient storage bodies. Parallel studies were conducted on iron-rich particles. A comparison of globoids from cotyledons of dry seeds with those of seedlings found that P, K, and Mg levels declined markedly, while Ca, Fe, Zn, and Mn levels increased significantly. A comparison of iron-rich particles showed that levels of P, K, Mg, and Ca changed, while Fe, Zn, and Mn remained unchanged. The iron-rich particles persisted during cotyledon greening and were definitely located in chloroplasts. This is the first report of such particles in chloroplasts of conifers.
Hydrologic and mineral budgets of New Jersey Pine Barrens upland forests following two intensities of fire
Authors: Boerner Ralph E. J. , Forman R. T. T.
Published: January 2008

The hydrologic and mineral budgets of upland forest sites in the New Jersey Pine Barrens exposed to different fire intensities were determined. Inputs from bulk precipitation and outputs to groundwater were monitored in an unburned control site, two sites burned by severe wildfire, and two sites burned by light prescribed burning. Fluxes of water, calcium, magnesium, and potassium to groundwater were highest in wildfire sites, intermediate in prescribed burn sites, and lowest in the unburned control. At all sites, outputs were the greatest during late-winter snowmelt. In the unburned site, outputs were essentially absent during the growing season, whereas in the wildfire sites outputs to groundwater were present year round. Rates of mineral and water output were inversely proportional to biomass and forest floor mass, which in turn depended upon fire intensity. Relative increases in output were similar to those reported following fire in other ecosystems. However, absolute rates of mineral output both before and after fire were lower in these sandy soils than those reported elsewhere, probably due to the low total mineral storage and variety of fire adaptations present in the Pine Barrens ecosystem.
Effects of soil acidity and phosphorus on the growth and nodule development of black alder
Authors: Seiler John R. , McCormick L. H.
Published: January 2008

Nodulated and nonnodulated black alder, Alnusglutinosa (L.) Gaertn., seedlings were grown in two acid mine spoils amended with five rates of lime (0.0, 1.0, 2.0, 4.0, and 8.0 g/kg of soil size particles) and three rates of phosphorus (0.0, 25.0, and 50.0 mg/kg of soil size particles). Height growth of nodulated seedlings was enhanced by lime and phosphorus. A significant lime X phosphorus interaction occurred for height growth of nodulated seedlings in both spoils: response to liming increased as the level of phosphorus was increased. Best height growth occurred at the highest lime and phosphorus levels. Nonnodulated seedlings failed to respond to either of the spoil amendments. Nodule weights of seedlings also were affected by lime and phosphorus and followed the same response pattern as shoot length.
Rooting of Fraser fir cuttings: effects of postseverance chilling and photoperiod during rooting
Authors: Miller N. F. , Hinbsley L. E. , Blazich F. A.
Published: January 2008

Terminal stem cuttings from 5-year-old Fraser fir (Abiesfraseri (Pursh) Poir.) stock plants were collected in early fall, when in a state of rest or winter dormancy. Cuttings were subjected to dark storage at 4 °C for 0, 2, 4, 6, 8, 10, or 12 weeks. Following storage, and prior to insertion into a rooting medium, cuttings were subjected to one of two treatments: nontreated, and wounding + indolebutyric acid (IBA). Cuttings received short- or long-days during a 10-week rooting period. Nonchilled cuttings did not root or break bud. High percent rooting occurred after 4–6 weeks of chilling, whereas visible terminal bud activity peaked after a 10-week chill. Rooting was primarily contingent upon IBA treatment and chilling, although long days had a strong promotive effect when cuttings were chilled less than 6 weeks.
Spectral radiation balance of poplar leaves using video techniques
Authors: Vlcek J. , Cheung E.
Published: January 2008

A simple method is described to measure spectral radiation absorptance of leaves (poplar clones) using video imaging in combination with narrow band-pass filters (in our case 40-nm bandwidth). Individual leaves can be measured in situ or several detached leaves can be measured at once to speed up the work. Both spectral reflectance and transmittance were measured using specially constructed small reflectance and transmittance targets. Data pertaining to 10 poplar clones sampled both from the open and closed canopy positions over a period of approximately 3 weeks yielded significant radiation absorption differences among the clones.
Drought-induced leaf abscission and whole-plant drought tolerance of seedlings of seven black walnut families
Authors: Parker William C. , Pallardy Stephen G.
Published: January 2008

Whole-plant drought tolerance and leaf abscission in response to drought of 5-month-old, half-sib black walnut (Juglansnigra L.) seedlings representing seven geographic origins were examined. Seedlings were subjected to six different levels of drought stress and then reirrigated. Mortality, leaf abscission, and refoliation responses were measured. Only one of 404 seedlings actually died. Survival of stem cambial tissues at predawn leaf xylem pressure potential values as low as −4.0 MPa was associated with the capacity for drought-induced leaf abscission. The percentage of seedlings exhibiting at least 80% leaf abscission increased linearly as predawn leaf xylem pressure potential decreased from −1.5 to −3.5 MPa. Although substantial differences in leaf abscission among families were observed, these differences were not statistically significant (P ≤ 0.05). Eighteen percent of all seedlings exhibited some degree of refoliation upon recovery of plant water status. However, the cumulative area of regrowth foliage was insignificant in terms of its adaptive value for resumption of photosynthetic activity following stress relief.
Epidemiology of dwarf mistletoe in western hemlock stands in south coastal British Columbia
Authors: Alfaro R. I. , Bloomberg W. J. , Smith R. B. , Thomson A. J.
Published: January 2008

Surveys of seven western hemlock (Tsugaheterophylla) stands in south coastal British Columbia using fixed-radius plots assessed dwarf mistletoe (Arceuthobiumtsugense) infection intensity level and spatial distribution patterns. Regression analysis indicated a close relationship between the plot infection index (average dwarf mistletoe rating of trees in a plot) and the percentage of infected trees. Plot infection index reached 4.0 when all trees in a plot were infected. Infected trees were either associated with widely spaced infection centers or were more or less evenly distributed throughout the stand. Spatial distribution pattern and spread rate were related to (i) the severity and distribution pattern of the initial inoculum sources, (ii) the manner of stand regeneration and resulting stand structure, and (iii) the presence of barriers to spread such as a high nonhost component and drastic slope increases. Tree mortality from dwarf mistletoe averaged 0.6% (range, 0–1.8%) and was much lower than mortality from other causes. On average, 9.3% of the trees had large dwarf mistletoe caused swellings on the lower third of the bole.
Ecological species groups of upland northern hardwood – hemlock forest ecosystems of the Sylvania Recreation Area, Upper Peninsula, Michigan
Authors: Spies Thomas A. , Barnes Burton
Published: January 2008

A tabular, field-oriented method of developing ecological species groups was applied in a classification study of upland northern hardwood – hemlock ecosystems in the Sylvania Recreation Area, Upper Peninsula, Michigan. Sixteen species groups were formed, consisting of a total of 76 upland herb, shrub, and moss species. The groups were constituted based on patterns of presence and absence and coverage values of species along gradients of soil fertility and soil moisture. The ecological responses of species within many of the groups were very similar. The environmental tolerances of the species groups in relation to soil fertility, moisture, forest floor conditions, and shade tolerance were described and contrasted. The groups were more differentiated along a fertility gradient than along a moisture gradient. The tabular method was relatively simple, yet effective in determining the species groups. The method is suitable for extensive land-classification activities; its essential element is that physiography, soil, and vegetation are examined simultaneously in the field. Species groups are more reliable in site classification and mapping than a subset of a few key species and the groups also simplify the use of many indicator species for field workers and ecosystem mappers.
Fire-induced changes in net value of timber: a sensitivity analysis
Authors: Mills Thomas J. , Flowers Patrick J.
Published: January 2008

The change in timber's present net value as a result of wildfire was estimated for 108 hypothetical fire situations in the northern Rocky Mountains of the United States. The net value changes, estimated by simulating timber yield changes on the fire site only, ranged from a loss of $964 to a gain of $1696 per acre ($2382 to $4191/ha) burned. The magnitude and sign of the net value changes were related to the fire size, fire severity, and timber management characteristics of the fire situation. The substantial impact of these separate fire situation characteristics suggests that efficient fire program management must consider the variability of the timber resource in detail. Net value change averages for large, heterogeneous areas would disguise considerable variation. The need for accurate timber net value change estimates can be filled by careful precalculation for standardized, situation-specific fire cases, thereby avoiding the computational inefficiencies of duplicative site-specific calculations.
Western gall rust and insect leader damage in relation to tree size in young lodgepole pine in Alberta
Authors: Bella I. E.
Published: January 2008

In a sample of 121 young lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) stands in naturally regenerated cut blocks near Hinton, Alta., strong positive correlations were observed in the incidence of gall rust (Endocronartiumharknessii (J. P. Moore) Y. Hiratsuka) and leader damage from terminal weevil (Pissodesterminalis Hopp.) and from pitch twig moth (Petrova spp.) with tree size in both thinned and unthinned stands. Although tests on a selected number of the largest trees from each plot showed no significant differences in incidence of the two pest categories between thinned and unthinned stands, thinning that retains the large trees may result in an increase in relative incidence of these pests unless special effort is made to cut damaged trees and retain undamaged ones.
Initial quantitative characterization of soil nutrient regimes. II. Relationships among soils, vegetation, and site index
Authors: Kabzems R. D. , Klinka K.
Published: January 2008

Relationships between soil properties, understory vegetation, foliar properties, and site index were examined in some Douglas-fir ecosystems on Vancouver Island. Multivariate summaries of variation in understory vegetation and foliar properties were highly correlated with the soil properties (mineralizable N, total N, and exchangeable Ca and Mg) that best characterized soil nutrient regimes of the ecosystems. The increases in soil nutrient availability were correlated with increased foliar N concentrations of the current year foliage. A consistent correlation was found between increased soil nutrient availability (particularly N, Mg, Ca) and decreased foliar Mn and Al. Site index of Douglas-fir was significantly greater on sites with greater quantities of most nutrients (particularly N, Mg, Ca) when sites with equivalent soil moisture regime were compared.
Age-related changes in shoot growth components of Great Basin bristlecone pine
Authors: Connor Kristina F. , Lanner Ronald M.
Published: January 2008

Shoots were collected from various-aged Great Basin bristlecone pine trees (Pinuslongaeva D.K. Bailey) at three locations to determine whether shoot growth, stem unit production, and stem unit length decreased with increasing tree age. Trees from a southern Utah site were 14–2052 years old, whereas those from two White Mountains, California, locations were 824–4712 years old. Variation in shoot length, stem unit production, and stem unit length were not significant when regressed on tree age (r2 = 0.010–0.237). The fact that shoots from older trees showed no sign of reduced growth when compared with those from younger trees suggests that diminishment of annual shoot increment is not a definitive sign of aging in Great Basin bristlecone pine.
Microbial respiration and biomass in soil of a lodgepole pine stand acidified with elemental sulphur
Authors: Visser S. , Parkinson D.
Published: January 2008

A study was conducted to determine the effects of elemental sulphur (So) dust pollution on pH, microbial respiration and biomass, glucose mineralization dynamics, and selected soil chemical characteristics in the organic and mineral soil of a Pinuscontorta Dougl. stand near Rocky Mountain House, Alberta. Six sampling sites were established 50 to 750 m downwind of a So block located at a sour gas processing facility. The sites represented a gradient in sulphur (S) concentrations (1072 to 35 800 μg•(g soil)−1) and pH (4.9 to 1.6). In the organic horizon, So dust significantly reduced the pH from a mean of 4.1 to 2.3 and microbial biomass from 753 to 130 mg C•(100 g dry weight soil)−1. Increasing acidification also reduced total Ca, Mg, K, Mn, and P. A reduction in the cations, P, and microbial biomass was particularly evident at a soil pH below 3.3. Glucose mineralization patterns were altered as a result of acidification. The time required by the soil microbial biomass to attain maximum CO2 efflux following glucose enrichment increased from 11 h in the least acidified soil (pH 4.1) to 38 h in the most acidified soil (pH 2.3). Soil respiration was not significantly affected by soil acidification. Microbial biomass was highly correlated with pH. The mineral soil demonstrated a decreasing trend in pH (5.0 to 3.7) with increasing S levels (79 to 499 μg•(g dry weight soil)−1), but no significant effects on respiration and biomass were detected. However, glucose utilization patterns revealed a tendency towards a slower responding and less efficient biomass with increasing acidity. The time to reach maximum CO2 efflux following glucose enrichment increased from 14 h in the least acidified site (pH 5.0) to 26 h in the most acidified site (pH 3.7). The use of biomass measurements coupled with glucose utilization patterns for providing insight into the effects of pollutant stress on soil microorganisms is discussed.
La conduite des jeunes peuplements de bouleaux jaunes (Betulaalleghaniensis Britton): caractéristiques morphologiques
Authors: Ouellet D. , Zarnovican R.
Published: January 2008

The morphological characteristics of a young yellow birch stand (Betulaalleghaniensis Britton) were studied according to class height and class development, according to the classification criteria set by IUFRO. The results show that the crown projection ratio, b/dhp, and the ratio h/dhp are strongly correlated to the social position and the vitality of the trees. During clearing, these two morphological ratios should be considered in distinguishing among primary, useful accessory, and harmful accessory trees. The differentiation of trees in social classes is emphasized by competition for growing space and will result in the modification of the dynamics of tree morphology and stem growth volume.
Microgeographic genetic variation of Sitka spruce in southeastern Alaska
Authors: Campbell Robert K. , Pawuk William A. , Harris Arland S.
Published: January 2008

Microgeographic genetic variation among populations of Sitka spruce on Mitkof Island in southeastern Alaska is described. In two common-garden environments, we evaluated genotypes of 208 parent trees from 114 locations in a 17 000-ha area. Two principal components accounted for most of the variation among locations in 11 traits measured to evaluate growth vigor and rhythm of 2-year-old seedlings. Regression analyses of factor scores derived from principal components revealed genetic gradients associated with elevation, slope, aspect, and west–east and north–south direction. Large amounts of additive genetic variation in factor scores occurred among trees within locations. When this variation within locations was used as a scale, variation among locations was also large. In an extreme case, locations differed in factor scores of the first principal component by about 3.0 units of the standard deviation of additive genetic variation in factor scores. Of the total differentiation in this case, elevational range (600 m) contributed 0.7 units of standard deviation, aspect contributed 0.9 units, and distance (16 km) from north central to southeastern parts of the island contributed 1.4 units.
Distribution and variation of extractable total phenols and tannins in the logs of four conifers after 1 year on the ground
Authors: Kelsey Rick G. , Harmon Mark E.
Published: January 2008

Concentrations of extractable total phenols and tannins have been analyzed in the outer bark, inner bark, sapwood, and heart wood from logs of four conifer species, after 1 year on the ground. To estimate decay rates, initial tissue densities were compared with those after 1 and 2 years of decomposition. The four species studied, Pacific silver fir (Abiesamabilis Dougl. ex Forbs), western hemlock (Tsugaheterophylla (Raf.) Sarg.), Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), and western red cedar (Thujaplicata D. Don) represent a gradient of decay resistance. Within a species, outer bark contained the greatest quantities of extractable total phenols followed by inner bark, heart wood, and sapwood. Outer barks also had the highest extractable tannin concentrations. Woody tissues contained very low concentrations of tannin compared with the barks. Total phenol concentrations were highest in the heart wood of red cedar, the most resistant, and lowest in the heart wood of silver fir, the least resistant. There was no obvious relationship between tannins, in any tissues, and the resistance gradient. Density measurements indicated minimal decay in all tissues after 1 year. At 2 years, the inner barks of Douglas-fir, western hemlock, and silver fir had decreased significantly. In general, tissues with the highest extractable phenols appear to be decomposing most slowly.
Effect of applied growth regulators and cultural treatments on flowering and shoot growth of Pinustabulaeformis
Authors: Sheng Chuxing , Wang Shasheng
Published: January 2008

Fourteen treatments expected to promote and regulate flowering were administered to 7-year-old seedlings of Chinese pine (Pinustabulaeformis Carr.), and three were administered to 11-year-old grafted propagules. The cultural treatments, including root pruning, stem girdling, polyethylene mulching, and injection of gibberellin A3 (GA3) significantly increased male cone bud production of the young seedlings. For female flowering, however, only GA4 injection, alone and in combination with root pruning, had a statistically significant positive effect. N6-benzyladenine (BA) injection significantly decreased both male and female cone-bud production. There was no synergistic effect between the cultural and the hormonal treatments on flowering of the seedlings. Treatments with naphthaleneacetic acid dramatically enhanced male cone bud production of the grafted propagules, but did so at the expense of female cone bud production. The hormonal treatments (GA3, GA4, and BA injection) all promoted vegetative shoot growth of the treated seedlings. The cultural treatments generally inhibited shoot length growth and had no significant effect on diameter growth.
Mass and nutrient content of decaying boles in an Engelmann spruce – subalpine fir forest, Rocky Mountain National Park, Colorado
Authors: Arthur Mary A. , Fahey Timothy J.
Published: January 2008

We classified dead bole wood in an old-growth Engelmann spruce – subalpine fir (Piceaengelmannii Parry – Abieslasiocarpa (Hook.) Nutt.) forest in Rocky Mountain National Park, Colorado, into decay classes and measured dead bole surface area, volume, biomass, and nutrient content. Biomass of dead boles was 70 Mg/ha, about half as large as aboveground live biomass in these forests. Net accumulation of N, P, Ca, and Na occurred with increasing decay. The N:P ratio varied little with decay, approaching a value of 20 in the most decayed wood, typical of that found in other studies of dead boles. Loss of K during bole decay exceeded the rate of weight loss, whereas Mg loss followed weight loss. The total pools of nutrients in dead boles and in parentheses, the amount of nutrients stored in dead boles as a percentage of total above- and below-ground living, forest floor, and dead wood nutrients were 92.2 kg N/ha (7%), 4.89 kg P/ha (5%), 67.9 kg K/ha (16%), 156.6 kg Ca/ha (12%), 28.9 kg Mg/ha (17%), and 0.74 kg Na/ha (9%). Storage of relatively high amounts of Ca in dead wood of most natural forests indicates that management could have a significant effect on its availability in the long term.
Genetic improvement of sugar maple for high sap sugar content. II. Relative effectiveness of maternal and biparental selection
Authors: Kriebel Howard B.
Published: January 2008

Sap sugar data taken in four progeny plantations of sugar maple (Acersaccharum Marsh.) were analyzed to evaluate breeding methods for high sap sugar concentration. Two of the plantations included progeny from open pollination of mass-selected trees, one included progeny from a clonal seed orchard, and one included progeny from a breeding experiment. The plantations differed in proportions of maternal selection and biparental selection employed. Maternal selection was ineffective as a means of achieving gain for high sugar bush productivity, whereas biparental selection was clearly effective. Gain in rogued progeny plantations from maternal selection was no greater than would be expected from roguing progenies of unselected parents. Low female parent – offspring correlations were attributed to nonrandom mating resulting from insect pollination, rather than low heritability. The use of lower testing "standard" trees in mass selection favors low or mediocre performance of progenies, because of the probability that standards will contribute to the progeny gene pool. Biparental selection was effective through (i) open intercrossing of high-performing seed orchard clones and (ii) controlled pollination of selected superior trees. Seed orchard progeny could be selected by age 13 years and subsequently rogued to final sugar bush spacing. Long-term data support a prediction that the mature sugar bush will average about 4.5% sap sugar concentration. One gallon (1 gal = 3.79 L) of maple syrup of that concentration requires 18.4 gal of sap, compared with an average of 43 gal required from Ohio sugar bushes. The gain from biparental selection and intensive roguing of progeny is estimated to be about 40% greater than similar roguing of plantations from unselected or maternally selected parents.
The moist strand and the burning bed
Authors: Weber R. O.
Published: January 2008

A guide to the propagation and extinction of a flame along a single strand of fine fuel is given. It relates the moisture of the single strand to the angle of inclination at which flame propagation is just sustained. The relationship between propagation along a single strand and through a bed composed entirely of single strands is also discussed.
An investigation of somatic variability for ribosomal RNA gene number in old-growth Sitka spruce
Authors: Strauss Steven H. , Howe Glenn T.
Published: January 2008

We studied variability in ribosomal RNA gene number in old-growth trees of Sitka spruce (Piceasitchensis (Bong.) Carr.). Total cellular DNA was extracted from two foliage samples taken from the ends of two major branches from each of 10 trees that were at least several hundred years old. Relative ribosomal RNA gene number was determined by probing slot blots with a cloned nuclear ribosomal gene from soybean. Through additional probings of the slot blots, these estimates were adjusted for residual variability in the amount of total genomic DNA blotted and the fraction of chloroplast DNA using multiple covariance analysis. Within trees, we found no indication of gene number differences among branches. Although small differences may have gone undetected, these results suggest that somatic variability of ribosomal RNA gene number is a minor source of genetic variability.
Evidence of periodicities related to climate and planetary behaviors in ring-width chronologies of Atlas cedar (Cedrusatlantica) in Morocco
Authors: Dutilleul Pierre , Till Claudine
Published: January 2008

Mean standardized 120-year ring-width chronologies of Cedrusatlantica (Endl.) Carrière (Atlas cedar) computed for four geographical regions of Morocco (Rif, Central Middle Atlas, Eastern Middle Atlas, High Atlas) and mean annual 49-year precipitation series computed for four bioclimatic strata that overlay the geographical regions were analyzed in the frequency domain. Their predominant frequency components were estimated at the end of a stepwise procedure that involved the analysis of a modified periodogram. A 7-year periodicity has been detected in all the precipitation series and in some of the tree-ring series. These ring-width indices also show periodicities of about 11 and 18.6 years, which have been assigned aposteriori to the planetary system dynamics, i.e., to sunspot activity and lunar nodal tide, respectively. Among-region differences in the year to year fluctuations of C. atlantica radial growth were statistically assessed using analysis of variance of the finite Fourier transform of the mean standardized ring-width chronologies for 39 sites located in the four geographical regions. In particular, they were assessed at frequencies corresponding to the detected periodicities related to climate and planetary behaviors. Low to high concordance levels have been observed among tree-ring series from different geographical regions, and these concordance levels were related to the sensitivity of Catlantica to limiting factors.