bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological and anatomical development in the Vitaceae. IV. Floral development in Parthenocissus inserta
Authors: Gerrath Jean M. , Posluszny Usher
Published: September 2007

The floral ontogeny of Parthenocissus inserta, based on histological and three-dimensional observations, is presented. The inflorescence primordium arises in a leaf-opposed position at two of three nodes. It becomes subtended by a bract, and then bifurcates equally to form a lateral and a main arm. Inflorescence branches are initiated on both arms to form a series of dichasia. The transition from inflorescence branch primordium to floral primordium is marked by the initiation of three sepal primordia. Subsequently a ring primordium forms as the fourth and fifth sepal primordia are initiated, resulting in a calyx which encircles the floral apex. Petals and stamens arise simultaneously as five common petal–stamen primordia, alternating with the sepals. They bifurcate to form separate petal and stamen primordia. The petals are greenish, valvate, hooded, and are separate at maturity. The tetrasporangiate anthers are introrse and pollen is tricolporate. The gynoecium arises as a ring primordium. Two septa arise from the inner gynoecial wall and the floral apex, and will eventually form an essentially two-loculed superior ovary. Two ovules are initiated from the base of each septum. Each of the four ovules is anatropous and bitegmic at maturity. A disc arises from the base of the gynoecium. It appears as five pinkish protuberances of the ovary base at maturity and secretes a nectarlike substance. The fruit is a one- to four-seeded blue-black berry.
Responses of arctic sedges to release from grazing: leaf demography of Carex × flavicans
Authors: Kotanen P. M. , Jefferies R. L.
Published: September 2007

The responses to herbivory of shoots of the sedge, Carex × flavicans, were investigated at La Pérouse Bay on the Hudson Bay coast in northern Manitoba. Demographic techniques were used to compare the production and turnover of leaves between plants of swards on which adults and goslings of the Lesser Snow Goose (Chen caerulescens caerulescens (L.)) fed and plants of swards from which geese were excluded. Within a growing season, release from grazing resulted in decreased production and turnover, and increased lifespans of leaves. The data indicate that plants of this species have the ability to modify patterns of leaf demography in response to the absence or presence of foraging by geese.
Acids from blue-stain diseased lodgepole pine
Authors: Ayer William A. , Migaj Barbara S.
Published: September 2007

The wood of blue-stain diseased lodgepole pine has been examined for the presence of 2,3-dihydroxybenzoic acid and ceratenolone, compounds believed to be responsible, in the form of their ferric chelates, for the blue coloration of the diseased wood. These compounds were not detected. Dehydroabietic acid, 15-hydroxydehydroabietic acid, 7α- and 7β-hydroxydehydroabietic acid, and 7-oxodehydroabietic acid were isolated. The 1H and 13C nuclear magnetic resonance spectra and mass spectra of the above mentioned compounds are reported.
First-year response of a Phragmites marsh community to seasonal burning
Authors: Thompson D. J. , Shay Jennifer M.
Published: September 2007

The effect of seasonal burning was determined on a stand of Phragmites australis with an understory of Teucrium occidentale, Urtica dioica, and three less abundant species. Each portion of the stand was subjected to one of three burn treatments: August 1979, October 1979, or May 1980. By August 1980, the summer-burned community had decreased in dominance and increased in species diversity, richness, and evenness. In contrast, these community characteristics were unaltered on the spring and fall burns. Understory species showed three different responses to season of burn: (1) Atriplex patula and Sonchus arvensis were absent on unburned plots; their aboveground biomass increased on summer burns owing to seedling establishment but did not increase on spring burns. (2) Cirsium arvense and Lycopus asper were fairly frequent on unburned plots but had low aboveground biomass; their aboveground biomass increased on summer burns owing to both vegetative spread and seedling establishment but did not change on spring burns. (3) Mentha arvensis, T. occidentale, and U. dioica had both high frequencies and biomass on unburned plots; their biomass was reduced on summer burns but increased on spring burns. Species with responses 1 and 2 increased in biomass to a lesser extent on fall burns, whereas those with response 3 declined in biomass on fall burns.
Flavonoid constituents of seed coats of Vicia faba (Fabaceae) in relation to genetic control of their color
Authors: Nozzolillo C. , Ricciardi L. , Lattanzio V.
Published: September 2007

Flavonoid aglycones were identified from Vicia faba L. seed coats corresponding to eight genetically determined colors. Myricetin predominates over quercetin in beige, black, brown, green, red, and violet seeds. Kaempferol is present in substantial amounts only in spotted seeds. White seeds have only trace amounts of quercetin and kaempferol and are the only ones without proanthocyanidins. Flavones of the apigenin type occur in all colors but white. Anthocyanins (malvidin, delphinidin, petunidin, and cyanidin glycosides) are present only in violet seeds and are obviously responsible for their color. The dark colors of black, brown, and red seeds apparently result from unidentified polymers. It is concluded that the two loci, a and b, proposed by Ricciardi et al. (1985) as the sites of genetic control of seed-coat color, control the amount and type of flavonoids produced: locus a that of flavonoid monomers (flavonols, etc.) and locus b that of flavonoid polymers (condensed tannins).
Effect of sodium fluoride treatments on the mitotic cycle of root-tip cells in jack pine seedlings
Authors: Zwiazek J. J. , Shay Jennifer M.
Published: September 2007

Fluoride-induced changes in the mitotic cycle were studied in root-tip cells of jack pine (Pinus banksiana Lamb.) seedlings using the metaphase accumulation method. Sodium fluoride treatments resulted in lengthening of the mitotic cycle. This was due to an increase in the duration of interphase. The duration of mitosis and individual mitotic phases was not affected by the treatments.
Le statut de la morphologie végétale
Authors: Cusset Gérard
Published: September 2007

This paper defines different states of mind that have been developed towards plant forms by professional botanists and others. A discussion leads to proposals for an open morphology, keeping a scientific status for this discipline. Key words: plant morphology, history of botany, philosophy of botany. [Journal translation]
Development of a new class of precast concrete pipes - a numerical evaluation
Authors: Naggar H El , Allouche E N , Naggar M H. El
Published: September 2007

The precast concrete pipe industry is in continuous pursuit to add value to its products to strengthen its market competitiveness against other pipe products. The research reported in this paper aimed at developing a new class of precast concrete pipes that will provide added value to the final user in comparison with existing products. The technology developed by the authors consists of lenses of a porous material that are used to create "conduits" within the wall of a precast concrete pipe, which are continuous across adjacent segments. These conduits can accommodate telecommunication lines (i.e., fibre optics) and other small diameter utilities. The concrete pipe provides protection for the smaller conduits while conserving underground right-of-way space. This paper describes the results of an extensive numerical study undertaken to evaluate the technical viability of the proposed conduit system. Key words: precast concrete pipe, cellular concrete pipe, finite element analysis, conduit system.
Impact of occasional overtime on construction labor productivity: quantitative analysis
Authors: Sonmez Rifat
Published: September 2007

Scheduled and occasional overtime practices have been used frequently in the construction industry. Past research indicated that continuous scheduled overtime could have a negative effect on labor productivity. The impact of occasional overtime on productivity is generally expected to be less than the impact of scheduled overtime. However, few studies have evaluated the effects of occasional overtime on productivity, which is the main objective of this paper. Productivity data for 234 weeks were collected for quantitative analysis. The t test was performed initially to determine the statistical significance of the impact of occasional overtime. The assessment of productivity data samples revealed possible deviations from the normal distribution. The Wilcoxon rank sum test was implemented as an alternative to the t test. The results of quantitative analysis indicate that moderate levels of occasional overtime did not have a significant impact on productivity. Based on the findings in this study, the potential advantages of occasional overtime practices are discussed.Key words: construction industry, labor productivity, occasional overtime, normality.
Project appraisal and selection using the analytic network process
Authors: Dikmen Irem , Birgonul M Talat , Ozorhon Beliz
Published: September 2007

Where prioritization and selection process of large-scale construction projects is concerned, governments should consider various quantitative and qualitative criteria when choosing the best project alternative. The traditional benefit–cost (BC) analysis has some drawbacks in terms of analyzing qualitative attributes that cannot be easily expressed in monetary terms. To eliminate this limitation, multicriteria decision-making techniques are proposed for the solution of project prioritization problems. In this paper, an analytic network process (ANP) model is developed to demonstrate how the project selection process can be carried out by considering both quantitative and qualitative factors, as well as their interrelations. The decision network is grouped under four subnetworks, namely benefits, costs, opportunities, and risks. The selected alternatives are real highway projects that are in the investment agenda of the Turkish government. Using the proposed network model, four investment alternatives are assessed by a team of experts and achieved results demonstrate that the ranking of project alternatives may significantly change when the ANP model is used instead of the classical B/C approach. Key words: analytic network process (ANP), multi-criteria decision making, project selection, benefit–cost analysis.
Development of an inspection system for cracks in a concrete tunnel lining
Authors: Lee Seung Yeol , Lee Sang Ho , Shin Dong Ik , Son Young Kap , Han Chang Soo
Published: September 2007

Over the last several decades, many concrete tunnels have been constructed for roads, highways, and railways. For safety in concrete tunnels, periodic inspections have been conducted using nondestructive testing technologies and techniques. However, nondestructive tests cannot replace visual inspection because of their slow and complicated procedures. For this reason, their use has been limited to precision inspections. Visual methods of assessment also require significant time commitments, and they produce subjective results regarding measured crack data. This study proposes an inspection system for the rapid measurement of cracks in tunnel linings and provides an objective method for assessing crack data for safety purposes. The system consists of both image data acquisition and analysis systems. The acquisition system takes images with charge-coupled device (CCD) line-scan cameras. The analysis system extracts crack information from the acquired images using image processing. Measured crack information includes the thickness, length, and orientation of cracks. To improve the accuracy of crack recognition, the geometric properties and patterns of cracks in concrete structures should be applied to image processing. This proposed system was verified through a series of experiments in both laboratory and field environments. Key words: crack, inspection, image processing, tunnel lining, tunnel safety.
Rational model for calculating deflection of reinforced concrete beams and slabs
Authors: Bischoff Peter H
Published: September 2007

Deflection control is an important performance criterion that needs to be satisfied to ensure serviceability of the structure for its intended use. The extent of cracking and amount of reinforcement affects the flexural rigidity, EI, of a reinforced concrete member and both the Canadian concrete design standard (CSA A23.3-04) and ACI Building Code (ACI 318-05) use an effective moment of inertia, Ie, that was originally proposed by Branson to compute beam deflection. This is an empirically derived equation that works well within a narrow range of limits corresponding to steel-reinforced concrete beams with a reinforcing ratio between 1% and 2%. However, the equation underestimates deflection for steel-reinforced concrete beams and slabs with a reinforcing ratio less than 1% and for most beams reinforced with low-modulus, fibre-reinforced-polymer (FRP) bars. Deflection of slender tilt-up wall panels can also be underestimated with Branson's equation. This paper provides an explanation of why the Branson equation does not always work well in predicting deflection, and presents a rational approach to develop an alternative expression for the effective moment of inertia that works equally well for both steel- and FRP-reinforced concrete at all reinforcing ratios. A rational expression is also introduced for continuous beams that uses an averaged moment of inertia, Ie,avg, to calculate beam deflection. Changes are included in a proposed revision to deflection prediction requirements specified in clause 9.8 of CSA A23.3-04.Key words: reinforced concrete, deflection, effective moment of inertia, serviceability.
Research quality, publications, and impact in civil engineering into the 21st century. Publish or perish, commercial versus open access, Internet versus libraries?
Authors: Chanson Hubert
Published: September 2007

A research project is only completed when it has been published and shared with the community. Referees and peer experts play an important role in controlling the research quality. While some new electronic tools provide further means of disseminating some research information, the quality and impact of the works remain linked with some thorough expert-review process and publication in international scientific journals and books; unethical publishing standards are not acceptable. The writer argues that the new electronic aids do not replace scholarship or critical thinking, although they have an impact on the working environment of civil engineers.Key words: research publications, quality, impact, peer reviews.
Structural features and functional domains of amassin-1, a cell-binding olfactomedin protein
Authors: Hillier Brian J. , Vacquier Victor D.
Published: September 2007

Amassin-1 mediates a rapid cell adhesion that tightly adheres sea urchin coelomocytes (body cavity immunocytes) together. Three major structural regions exist in amassin-1: a short β region, 3 coiled coils, and an olfactomedin domain. Amassin-1 contains 8 disulfide-bonded cysteines that, upon reduction, render it inactive. Truncated forms of recombinant amassin-1 were expressed and purified from Pichia pastoris and their disulfide bonding and biological activities investigated. Expressed alone, the olfactomedin domain contained 2 intramolecular disulfide bonds, existed in a monomeric state, and inhibited amassin-1-mediated clotting of coelomocytes by a calcium-dependent cell-binding activity. The N-terminal β region, containing 3 cysteines, was not required for clotting activity. The coiled coils may dimerize amassin-1 in a parallel orientation through a homodimerizing disulfide bond. Neither amassin-1 fragments that were disulfide-linked as dimers or that were engineered to exist as dimers induced coelomocytes clotting. Clotting required higher multimeric states of amassin-1, possibly tetramers, which occurred through the N-terminal β region and (or) the first segment of coiled coils.
Platelet-derived growth factor BB modulates PCNA protein synthesis partially through the transforming growth factor beta signalling pathway in vascular smooth muscle cells
Authors: Pan Dabin , Yang Junwei , Lu Fengxiang , Xu Di , Zhou Lei , Shi Aiwu , Cao Kejiang
Published: September 2007

PDGF-BB (Platelet-derived growth factor BB) and TGF-β1(transforming growth factor β1) are important growth factors in the modulation of vascular smooth muscle cell (VSMC) proliferation and PCNA (proliferating cell nuclear antigen) expression in VSMCs. PCNA expresses at a high level in proliferating cells. The present study aims to assess the effects of PDGF-BB-induced overexpression of TGF-β1 on PCNA in VSMCs. The downstream proteins of the TGF-β signalling system in VSMCs, including TGF-β type I receptor (ALK-5 in VSMCs), Smurf2, Smad2, pSmad2/3, Smad4, and Smad7, were also investigated. Our results revealed that PDGF-BB significantly increased the expressions of TGF-β1 and PCNA, and the increase in PCNA can be partially inhibited by neutralizing anti-TGF-β1 antibody. Furthermore, PDGF-BB increased the expression of ALK-5, Smurf2, pSmad2/3, and Smad4, but lowered the levels of Smad2 and Smad7; these alterations were partially restored by neutralizing anti-TGF-β1 antibody. These findings suggest that PDGF-BB promotes PCNA expression in VSMCs partially through TGF-β1 overexpression, and that the TGF-β signalling system involves the molecular mechanism of PDGF-BB in VSMCs.
The transcription of the gene for iso-orotate decarboxylase (IDCase), an enzyme of the thymidine salvage pathway, is downregulated in thepregcmutant strain of Neurospora crassa grown under phosphate starvation
Authors: Leal Juliana , Squina Fabio M. , Martinez-Rossi Nilce M. , Rossi Antonio
Published: September 2007

The preg gene encodes a cyclin-like protein that is implicated in the derepression of nucleases and phosphatases that scavenge phosphate from the environment. To better understand the regulatory role of the preg gene product, the differential display reverse transcriptase – polymerase chain reaction was used to isolate transcripts differentially expressed in the pregcmutant strain of the mold Neurospora crassa grown under phosphate starvation, at pH 7.8. Two transcripts, whose differential expressions were confirmed by Northern blotting, were downregulated in a strain of N. crassa carrying a loss-of-function mutation in the preg gene (pregcallele). These transcripts revealed genes coding for enzymes involved in the thymidine salvage pathway (iso-orotate decarboxylase) and in the biosynthesis of coenzyme Q (ubiquinone C-methyltransferase), which may be relevant to a further understanding of the molecular events involved in the phosphorus sensing in N. crassa.
Root movement and root damage of red spruce and balsam fir on subalpine sites in the White Mountains, New Hampshire
Authors: Rizzo D. M. , Harrington T. C.
Published: September 2007

Crown dieback and mortality of red spruce and balsam fir in the subalpine zone of the northern Appalachian Mountains have been attributed to wind-induced crown and root damage. Vertical root movements, damage to roots and crowns, and growth rate were measured on wind-exposed spruce and fir trees near canopy gaps at Kancamagus Pass (875 m elevation) and Wildcat Mountain (1160 m) in the White Mountain National Forest, New Hampshire. Root movements were significantly correlated with windspeed, crown exposure, and depth of soil to rock. Woody roots that had made movements in excess of 10 mm had fewer small (1–3 mm diameter) roots, more abrasion wounds, and a greater amount of nonconducting (dry or discolored) xylem than roots that had made smaller movements. Hydraulic conductivity was significantly reduced in roots with greater than 40% xylem cross-sectional area that was nonconducting. Spruce and fir trees at gap margins grew slower and had more root and crown damage than trees sheltered within the canopy. Decreases in growth rate of spruce and fir trees at both sites during the past 20 years were significantly correlated with wind exposure and some of the root and crown damage variables.
Canker diseases of Douglas-fir seedlings in Oregon and Washington bareroot nurseries
Authors: Hansen E. M. , Hamm P. B.
Published: September 2007

Canker diseases in northwestern forest nurseries have been referred to collectively as top blight. To distinguish among the various symptoms and their associated fungi, we made systematic observations of and isolations from Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings through two crop cycles in four northwestern nurseries, and suspect fungi were subjected to pathogenicity testing. Five diseases were distinguished. Hypocotyl rot, caused by Fusariumoxysporum, kills seedlings during their first growing season. Upper stem canker, caused by Phomaeupyrena and Fusariumroseum, girdles seedlings in midstem in the fall of their 1st year. Lower stem canker, also caused by P. eupyrena and F. roseum, kills seedlings in the winter or early spring of their 2nd year and is associated with soil collars built up by splashing water. Botrytis and Phomopsis cankers occasionally kill new shoots during the 2nd year. Not all diseases are damaging every year or in all nurseries.
Simultaneous estimation with a squared error loss function
Authors: Deusen Paul C. Van
Published: September 2007

Estimation based on minimizing simple squared error loss functions (SSLF) is shown to be very similar to the seemingly unrelated regressions technique (SUR). This leads to the possibility of obtaining asymptotic standard errors for parameter estimates, to the consideration of other econometric methods, and to the availability of standard software. An example compares an SSLF with SUR, and one way is given to reformulate simultaneous fitting of compatible taper and volume equations so that it falls into the SUR framework.
Aerial application of verbenone reduces attack of lodgepole pine by mountain pine beetle
Authors: Shea Patrick J. , McGregor Mark D. , Daterman Gary E.
Published: September 2007

Mountain pine beetle, Dendroctonusponderosae Hopkins, is the primary pest affecting lodgepole pine, Pinuscontorta var. latifolia Engelm., ecosystems in western North America. In 1988, aerial treatments of the antiaggregation pheromone, verbenone, were applied to lodgepole pine stands infested with mountain pine beetle in northwestern Montana. The pheromone was formulated by PHERO TECH Inc. in controlled-release, cylindrical 5 × 5 mm plastic beads and applied without benefit of a sticker at the rate of 54 g verbenone per hectare. There were significantly fewer successfully attacked trees on the treated plots, as evidenced by (i) a fourfold greater incidence of current-year attacked trees per hectare in the untreated check plots and (ii) the significantly lower (α = 0.05) ratio of 1988:1987 attacked trees in the treated plots. Further, the number of trees per hectare resisting attacks (as reflected by number of trees pitching out bark beetles) was higher (α = 0.05) in the treated plots. More pitch outs occurred in treated plots presumably because avoidance of verbenone by beetles reduced the number of beetles below that needed to overcome the natural resistance of attacked trees.
Soil nitrogen availability influences seasonal carbon allocation patterns in sugar maple (Acersaccharum)
Authors: Burke Marianne K. , Raynal Dudley J. , Mitchell Myron J.
Published: September 2007

The influence of soil N availability on growth, on seasonal C allocation patterns, and on sulfate-S content in sugar maple seedlings (Acersaccharum Marsh.) was tested experimentally. Relative to controls, the production of foliage doubled in response to high N availability, and the production of foliage, stems, coarse roots, and fine roots was halved in response to N deprivation. The period of foliage production was lengthened by fertilization and the period of fine root production was shortened by N deprivation compared with controls. In August, a shift in priority C allocation from foliage to roots occurred in the N-deprivation treatment. Therefore, during this month alone, the shoot to root ratio was greater in fertilized plants (1.0) than in N-deprived plants (0.5). Allocation to storage reserves was highest in N-deprived and lowest in fertilized plants (average 160 vs. 125 mg glucose/g biomass produced), and storage in roots of unfertilized plants commenced earlier (August) than in fertilized plants (after September). This resulted in unfertilized plants having higher fine root starch concentrations (5.2%) than fertilized plants (4.0%) in December, although sugar concentrations were similar (5.7%). The lengthened season of shoot growth and the low starch to sugar ratios in fine roots of fertilized plants are symptoms consistent with a higher risk of frost injury and microbial pathogen infection. Although soil N availability did not influence the sulfate-S content in foliage, N deprivation resulted in higher organic S to N ratios. This suggests that more S-containing proteins are produced when N availability is poor.
Effects of plantation density and spacing on competitive interactions among half-sib families of maritime pine
Authors: Euler Fredrik von , Baradat Philippe , Lemoine Bernard
Published: September 2007

The effects of competition among eight half-sib families of the Landes geographical race of maritime pine (Pinuspinaster Ait.) were studied in a field trial involving four spacings with two replications, in southwestern France. Families were picked from the open-pollinated progeny in a clonal seed orchard. Interfamily competition was controlled in 30-tree plots, with two families planted alternately in a checkerboard pattern. Each family was represented in one pure and two mixed plots, according to a balanced, incomplete, diallel design. Static competition effects from 4 to 16 years were assessed using (i) a diallel ANOVA model and (ii) a factorial ANOVA model. In the first model, genetic variance was split into a between-plot (kind of mixture) and a within-plot component. In the second model, components due to the direct effect (measured family) and the associate effect (competitor family) were separated. Genetic variance was much more significant at high density (2500 trees/ha) than at low density (1250 trees/ha). At high density, self-thinning occurred at age 16. With square spacing, a significant part of genetic variance, both between and within plots, was attributable to principal effects of families, direct as well as associate. With rectangular (1:4 ratio) spacing, genetic variance was chiefly expressed as family interaction at the plot level and reached a maximum at a more advanced age. Mixed plots averaged significantly better than pure plots for both height and girth in the rectangular spacing modality. Favourable root interaction between families is suggested as the reason for this effect.
Effects of ambient acidic rain on cation concentrations in leaves of Acersaccharum and Cornusflorida
Authors: Muir Patricia S.
Published: September 2007

Are foliar concentrations of inorganic cations measurably altered by ambient acidic rain? Leaves of Acersaccharum Marsh. and Cornusflorida L. were collected before and after seven rains, washed, and analyzed for concentrations of Ca2+, Mg2+, and K+. Leaf rinse water and the inorganic composition of each rain were also analyzed. All samples were collected in Indianapolis, Indiana, during June–September 1986–1987. Rain pH ranged from 3.6 to 4.6, volumes from 0.1 to 1.9 cm, and durations from 1 to 16 h. Most rains were net cleansers of leaf surfaces; concentrations of cations, SO42−, and NO3− in leaf rinse water were generally higher pre- than post-rain, or were unchanged by rain exposures, and leaf rinse water was more acidic after rains. Pre- versus post-rain changes in cation concentrations in washed leaves were generally small (±7%) compared with amounts present in leaves, and few differences were statistically significant (most p > 0.05). The changes in foliar cation concentrations were not correlated with rain pH, duration, volume, or date. These results suggest that short-term exposure to rain with pH typical of rain in much of the eastern United States is unlikely to have direct effects on foliar nutrient status, at least on fertile soils.
Croissance en hauteur à long terme de la régénération préétablie dans des pessières noires boréales régénérées par marcottage, au Québec
Authors: Paquin Raynald , Doucet René
Published: September 2007

Height-growth patterns of black spruce (Piceamariana (Mill.) B.S.P.) in the boreal forest were studied in layer-origin stands released by clear-cutting in the first half of this century. Most stems responded to release brought about by clear-cutting of the main stand. Initially, small stems responded more rapidly and more strongly, but their height-growth rate culminated between 20 and 30 years following release, the same period when height-growth rate culminated for the taller, older stems. After the culmination period, growth rates were independent of height at the time of release. Consequently, the taller stems at time of release were able to maintain their dominant position. Height growth over the recent years indicates that this position could be maintained in the years to come, and even indefinitely. It seems that second-growth black spruce stands behave like even-aged stands despite their uneven-aged structure. Consequently, years since release and stem height are more accurate measures of stem effective age than total age. Moreover, the taller stems in the understory, which are usually considerably older, should be considered to be as valuable as smaller regeneration when a stand is cut.
Resistance of graft-compatible and graft-incompatible Pseudotsugamenziesii rooted cuttings to Phellinusweirii
Authors: Entry James A. , Vance Nan C. , Copes Donald L.
Published: September 2007

One-year-old rooted cuttings taken from 23- and 26-year-old graft-compatible and graft-incompatible Pseudotsugamenziesii (Mirb.) Franco were inoculated with one of three isolates of Phellinusweirii. After 20 months in a greenhouse, infection frequency and severity were significantly greater in the graft-incompatible cuttings. Cellulose concentration in the root tissue was higher in graft-incompatible than graft-compatible cuttings. Concentrations of lignin, phenolic compounds, and tannins were higher in graft-compatible than graft-incompatible cuttings. Cellulose concentration had a positive linear correlation (r2 = 0.84) with the P. weirii infection rating. The concentration of phenolic compounds and lignin in secondary root tissues was negatively correlated with the infection rating (r = 0.73 and 0.84, respectively). The lignin/cellulose and phenolic/cellulose ratios were negatively correlated with the infection rating of P. weirii infection in a linear relationship (r2 = 0.82 and 0.77, respectively). White-rot fungi cannot use tree defense compounds, such as lignin and phenolics, as the sole energy source; an alternate energy source is necessary to degrade these compounds. The lignin/cellulose and phenolic/cellulose ratios in the roots may be important measurements to explain the host–pathogen response of P. weirii infection.
Competition for nitrogen between Pinusradiata and pasture. II. Trends in plant and soil processes
Authors: Clinton P.W. , Mead D.J.
Published: September 2007

15N-labelled nitrogen fertilizer was used to examine the competition for N between 4-year-old Pinusradiata D. Don and pasture grasses during one 8-month growing season. Availability and tree and pasture uptake of 15N-labelled fertilizer applied in spring were measured. Larger quantities of 15NO3−-N than 15NH4+-N remained available in the soil throughout the growing season. However, P. radiata assimilated similar quantities of 15N when supplied as 15NO3−-N or 15NH4+-N and uptake by pasture herbage was greater for 15NO3−-N than for 15NH4+-N. Removing pasture by spraying with herbicide increased the availability of soil 15N soon after application and doubled the uptake of 15N by P. radiata although the pattern of N uptake was not greatly affected.
Landscape-scale heterogeneity in lodgepole pine serotiny
Authors: Tinker Daniel B. , Romme William H. , Hargrove William W. , Gardner Robert H. , Turner Monica G.
Published: September 2007

A 1992 study of serotiny in lodgepole pine (Pinuscontorta Dougl. ex Loud. var. latifolia Engelm.) in Yellowstone National Park asked four questions: (i) are there morphological characteristics that can be used to estimate pre-fire proportion of serotinous trees in forests that burned in 1988?; (ii) at what spatial scale does percent serotinous trees vary across the landscape?; (iii) which environmental factors are correlated with serotiny?; and (iv) what is the relationship between prefire serotiny and postfire lodgepole pine seedling density? We first sampled cone characteristics in serotinous and nonserotinous trees along four 2950-m transects in unburned forests, and examined burned trees nearby. Results indicated that asymmetrical cones and an acute angle of cone attachment to the branch were reliable indicators of serotiny even in burned trees. We then sampled nine patches of lodgepole pine forest that had burned in 1988, and varied in size from 1–3600 ha. We sampled serotiny at varying intervals along two perpendicular transects that crossed in the center of each patch. At each sample point, the 12 nearest canopy lodgepole pines were classified as serotinous or nonserotinous. We concluded that the percentage of serotinous trees is most variable at intermediate scales of 1–10 km, and is relatively homogeneous at both fine scales (<1 km) and at very broad scales (tens of kilometers). Percent serotiny was generally more variable and greater at low to middle elevations. Prefire density of serotinous trees was a more important predictor of postfire seedling density than aspect, slope, or soil type. These findings have important implications for landscape-level patterns in postfire regeneration of lodgepole pine.
Modelling stomatal conductance in a northern deciduous forest, Chalk River, Ontario
Authors: McCaughey J. Harry , Iacobelli Antonio
Published: September 2007

Modelling results of stomatal conductance of trembling aspen (Populustremuloides Michx.) and white birch (Betulapapyrifera Marsh.) are reported. Stomatal conductance for the two species was related to global solar radiation, vapour pressure deficit, and air temperature using both linear and nonlinear least squares approaches. Both approaches provided an equally poor fit when relating the large scatter of stomatal conductance data to each of the environmental variables separately. However, an additive, multiple linear regression model and a multiplicative, nonlinear least squares model were able to explain between 50 and 62% of the variability in stomatal conductance when all three environmental variables were included in the models. The two models were able to track changes in stomatal conductance from one half-hour period to the next.
Germination and early growth of western larch (Larixoccidentalis), alpine larch (Larixlyallii), and their reciprocal hybrids
Authors: Carlson Clinton E.
Published: September 2007

Reciprocal cross pollinations between western larch (Larixoccidentalis Nutt.) and alpine larch (L. lyallii Parl.) were done in Spring, 1991. The cross to alpine larch females was highly successful; 63% of the seeds developed mature embryos and 79% germinated. However, the cross to western larch females resulted in only 4% filled seed of which 68% germinated. Open-pollinated western larch and alpine larch averaged 26 and 32% filled seed with 48 and 44% germination, respectively. Less than 1% of the alpine larch hypocotyls were reddish in color; most of them were green. About 15% of the western larch and about 17% of the hybrids from alpine larch females had reddish hypocotyls, whereas hybrids from western larch females were intermediate between western larch and alpine larch. Hybrid seed began germinating before the parental types and initial height growth exceeded that of the parental types. However, 4 months following germination, western larch seedlings were ca. four times taller than the hybrids and 10 times taller than alpine larch. Stems of hybrids were significantly thicker than those of either western larch or alpine larch. Hybrid seedlings are robust, stocky, and may be useful in revegetating cold, moist sites between the elevational ranges of alpine and western larch.
Classification of spruce beetle hazard in Lutz spruce (Picea × lutzii) stands on the Kenai Peninsula, Alaska
Authors: Reynolds K.M. , Holsten E.H.
Published: September 2007

Stand data from Lutz spruce (Picea × lutzii Little) forest types occurring on the Kenai Peninsula were analyzed by tree-based classification to develop a decision tree for classifying spruce beetle (Dendroctonusrufipennis Kby.) hazard. Model development and validation data sets contained 100 and 34 stand observations, respectively. The final decision-tree structure yielded seven possible hazard outcomes based on total stand basal area, percentage of total basal area composed of spruce, percentage of spruce basal area composed of trees with diameter >25 cm, stand elevation, and stand aspect. Three paths in the decision tree led to low-hazard outcomes (spruce basal area loss ≤10%); one path led to a high-hazard outcome (spruce basal area loss >40%). No paths through the decision tree led to a medium-hazard outcome (spruce basal area loss >10%, but ≤40%), but three less precise outcomes of low–medium and medium–high hazard were considered useful and retained in the final model. Results of model verification were considered very acceptable; in the worst case, predictions of high hazard were correct for 73% of the observations. Model validation results were also considered very acceptable considering the small number of observations available for this phase of analysis.
The influences of temperature and soil water on growth, photosynthesis, and nitrogen fixation of red alder (Alnusrubra) seedlings
Authors: Hawkins B.J. , McDonald S.
Published: September 2007

A 3 × 2 factorial experiment was conducted to investigate the interaction of temperature and soil water status on the growth, photosynthetic, transpiration, and nitrogen fixation rates of 2-month-old red alder (Alnusrubra Bong.) seedlings. Three day: night temperature treatments, 15:10 °C, 20:10 °C, and 25:10 °C were used. Two soil-water treatments kept pots between 85 and 100% of field capacity (wet) and 70–85% of field capacity (dry). Treatment effects on growth, net photosynthetic, transpiration and nitrogen fixation rates, plant water potential, and foliar nutrient concentration were measured over a 9-week period. The greatest seedling growth occurred at 25 °C day temperatures, while 20 and 25 °C days produced the greatest nodule growth. The allocation of biomass to roots increased with decreasing temperature. The highest rates of net photosynthesis occurred at 15 and 20 °C whereas transpiration was greatest at 25 °C. Plant water stress was greatest at 25 °C. The difference in plant water potential between the wet and dry treatments was only 0.04 MPa, which was not great enough to produce significant effects on growth or photosynthesis. Nitrogen fixation rates were highest in the wet treatment seedlings at 20 and 25 °C.
Viability tests for estimating root cold tolerance of black spruce seedlings
Authors: Blgras Francine J. , Calmé Sophie
Published: September 2007

After freezing tests, various methods for evaluating root damage were compared and correlated to the regrowth of 16-week-old containerized black spruce seedlings (Piceamariana (Mill.) B.S.P.) hardened in growth chambers. During the hardening regime, three experiments were performed. The first experiment evaluated the influence on the test results of washing the roots before or after a freezing test and compared the frost sensitivity of fine roots (<0.3 mm), larger roots (>0.3 mm), and whole root systems. The second experiment tested the effect of pressures of 0.05, 0.10, and 0.15 MPa on water loss. Experiment 3 compared four viability tests: electrolyte leakage, ninhydrin reactive compounds leakage, phenolic leakage, and water loss. Results were as follows: (i) washing the roots before or after the freezing test did not affect the results of the ninhydrin reactive compounds test; (ii) fine roots (<0.3 mm) were more sensitive to freezing damage than larger roots (>0.3 mm); (iii) sampling of fine roots (<0.3 mm), larger roots (>0.3 mm), or whole root systems gave different results for the ninhydrin reactive compounds test; (iv) tests of electrolyte leakage, phenolic leakage, and ninhydrin reactive compounds leakage had the ability to indicate tissue damage; (v) high values of these variables were associated with poor seedling regrowth; (vi) root water potential also indicates tissue damage but is less correlated to regrowth than electrolyte leakage, phenolic leakage, and ninhydrin reactive compound leakage; and (vii) the water-loss test seems less reliable than the others.
Seasonal and geographic origin effects on cold hardiness of white spruce buds, foliage, and stems
Authors: Simpson David G.
Published: September 2007

Cold hardiness of dormant vegetative buds from white spruce (Piceaglauca (Moench) Voss) trees originating from throughout the species' North American range was measured by differential thermal analysis between August and April at Vernon, B.C. Buds were least hardy in early fall (low temperature exotherm −12 to −25 °C) and most hardy midwinter (low temperature exotherms −20 to −34 °C). Buds of northerly origin trees were more hardy in early fall (September–October) than buds of more southerly origin trees. Similar results were observed for foliage and stem tissue in early fall using electrolyte leakage measurements following −16 °C freezing.
Evaluation of baroreflex control of heart rate in renovascular hypertensive mice
Authors: Peotta Veronica A. , Gava Agata L. , Vasquez Elisardo C. , Meyrelles Silvana S.
Published: September 2007

The objective of the present study was to evaluate the baroreflex and the autonomic control of heart rate (HR) in renovascular hypertensive mice. Experiments were carried out in conscious C57BL/6 (n = 16) mice 28 days after a 2-kidney 1-clip procedure (2K1C mice) or a sham operation (sham mice). Baroreflex sensitivity was evaluated by measuring changes in heart rate (HR) in response to increases or decreases in mean arterial pressure (MAP) induced by phenylephrine or sodium nitroprusside. Cardiac autonomic tone was determined by use of atropine and atenolol. Basal HR and MAP were significantly higher in 2K1C mice than in sham mice. The reflex tachycardia induced by decreases in MAP was greatly attenuated in 2K1C mice compared with sham mice. Consequently, the baroreflex sensitivity was greatly decreased (2.2 ± 0.4 vs. 4.4 ± 0.3 beats·min–1·mmHg–1) in hypertensive mice compared with sham mice. The reflex bradycardia induced by increases in MAP and the baroreflex sensitivity were similar in both groups. Evaluation of autonomic control of HR showed an increased sympathetic tone and a tendency to a decreased vagal tone in 2K1C mice compared with that in sham mice. 2K1C hypertension in mice is accompanied by resting tachycardia, increased predominance of the cardiac sympathetic tone over the cardiac vagal tone, and impairment of baroreflex sensitivity.
Endothelial expression of endoglin in normocholesterolemic and hypercholesterolemic C57BL/6J mice before and after atorvastatin treatment
Authors: Nachtigal Petr , Pospisilova Nada , Jamborova Gabriela , Pospechova Katerina , Solichova Dagmar , Andrys Ctirad , Zdansky Petr , Semecky Vladimir
Published: September 2007

Endoglin (CD105) is a homodimeric transmembrane glycoprotein strongly related to transforming growth factor (TGF)-β signaling and many pathological states. In this study, we wanted to evaluate whether endoglin is expressed in normocholesterolemic and hypercholesterolemic C57BL/6J mice as well as whether it is affected by atorvastatin treatment in these mice. C57BL/6J mice were fed with chow diet or an atherogenic diet for 12 weeks after weaning. In 2 atorvastatin-treated groups, mice were fed the same diets (chow or atherogenic) as described above except atorvastatin was added at the dosage of 10 mg·kg–1·day–1for the last 8 weeks before euthanasia. Biochemical analysis of blood samples revealed that administration of atherogenic diet significantly increased levels of total cholesterol, VLDL, LDL, and decreased levels of HDL. Atorvastatin treatment resulted in a significant decrease in total cholesterol and VLDL only in mice fed by atherogenic diet. Quantitative stereological analysis revealed that atorvastatin significantly decreased endothelial expression of endoglin in C57BL/6J mice fed the atherogenic diet. In conclusion, we demonstrated that endothelial expression of endoglin is upregulated by hypercholesterolemia and decreased by the hypolipidemic effect of atorvastatin in C57BL/6J mice, suggesting that endoglin expression could be involved in atherogenesis.
Fine spatial scale phenotypic divergence in wood frogs (Lithobates sylvaticus)
Authors: Meier P.T.
Published: September 2007

I studied local divergence in growth, a trait previously shown to be both phenotypically plastic and heritable, among wood frog (Lithobates sylvaticus (LeConte, 1825)) tadpoles inhabiting four ponds within a continuous woodland. Mark–recapture results revealed very low levels of migration among ponds as close as 35 m and no more than 185 m apart. Common garden experiments conducted at two temperatures revealed consistent year-to-year patterns of phenotypic divergence in tadpole growth performance among the four pond populations. The divergence in growth performance was conserved when controlling for parental effects via half-sibling experiments. Results of cross-transplant experiments suggest that the divergence in tadpole growth reflected either genetic drift or adaptation to local pond conditions. Taken together, the results suggest that divergence in growth performance among the tadpoles from the four ponds is the result of selection or genetic drift reinforced by low levels of gene flow among pond populations.
ALIGNING R&D TO BUSINESS — A LONGITUDINAL STUDY OF BU CUSTOMER VALUE IN R&D
Authors: FORTUIN FRANCES T. J. M. , (ONNO) OMTA S. W. F.
Published: September 2007

In large technology-based firms, especially in long life cycle industries, often a tension exists between corporate R&D and the business unit (BU) customers. The long term R&D orientation needed to come to the more radical (even disruptive) innovations for the long term survival of the prospector firm being at odds with the need of the BUs for more incremental "sustaining" innovations for their day-to-day activities. This paper takes a new approach to this problem by analyzing the corporate R&D to business relationship from a customer value perspective by identifying R&D flexibility, R&D communication, strategic alignment and R&D performance as the main attributes of the value map of the BU customers of corporate R&D. We then present the Cusvalin instrument (Customer Value Learning in INnovation) that was constructed to overcome the R&D to business incongruence by providing feedback on the gaps between the value maps of R&D and their BU customers. This instrument has been tested in a longitudinal survey from 1997 through 2002 (696 respondents) in a large technology-based supplier company (±30 000 employees world wide). It is concluded that the Cusvalin model is an effective instrument to monitor the strategic alignment of R&D and the BUs, and ultimately leads to better R&D performance, as perceived by the BU customers. From the longitudinal analysis it is concluded that a system that balances radical innovation (via Technology Board-funding, in which R&D management, headquarters, and BU directors jointly decide on long-term radical R&D projects) and incremental innovation (via BU unit-funding) is effective in providing strategic alignment between R&D and business.