bluuebunny/crossref_metadata_2025 huggingface dataset:
Whiplash risk estimation based on linked hospital–police road crash data from France and Spain
Authors: Martin J-L , Pérez K , Marí-Dell’Olmo M , Chiron M
Published: June 2008

Objectives:

To investigate potential risk factors for whiplash injury as a function of crash configuration and driver’s characteristics, and to provide information on over-reporting and under-reporting of whiplash.

Design:

A case–control study of drivers involved in two-car injury collisions. Cases were drivers who had a diagnosis of whiplash injury, with or without another injury. Controls were drivers without diagnosed whiplash injury.

Setting:

Hospital registries linked to police crash databases for Barcelona (Spain) and the “Département du Rhône” (France).

Main outcome measures:

Relative risks of whiplash and 95% confidence intervals were estimated using a modified Poisson regression.

Results:

Of the 8720 drivers involved in car-to-car crashes recorded in the French database, 12.2% were diagnosed with whiplash; the corresponding figure in the Spanish database was 12.0% of 7558 drivers. Female drivers and drivers in rear-impact collisions were most likely to have a whiplash diagnosis, although the absolute number of whiplash cases was greater in front and side impacts. Wearing a seatbelt, being in a heavier car, and age greater than 65 years were associated with a lower risk of whiplash injury. Drivers with other injuries were also more often diagnosed as having a whiplash injury, except the most severely injured.

Conclusions:

Devices aimed at reducing the occurrence of whiplash injuries, such as dynamic headrest systems, should be adapted to the characteristics of at-risk occupants, especially women, and should address the mechanics of front and side impacts in addition to rear impacts.
Paraprofessional home visitation program to prevent childhood unintentional injuries in low-income communities: a cluster randomized controlled trial
Authors: Swart L , van Niekerk A , Seedat M , Jordaan E
Published: June 2008

Objective:

To investigate the effectiveness of a paraprofessional home visitation program (HVP) to improve home safety and prevent injuries among children living in low-income settings.

Methods:

The HVP was implemented in two low-income communities in South Africa. In each community, approximately 200 households were randomly selected for the trial. Eligible households were those with children aged ⩽10 years. Intervention households received four visits, one every two weeks, by trained paraprofessionals that focused on a specific injury topic and consisted of: information dissemination about specific injury prevention practices; home inspection accompanied by information about home hazards; and the supply of safety devices. The key outcomes to measure the presence of home hazards were scores for burns (safety practices, paraffin, and electrical), poisoning, and falls.

Results:

Significant reductions were found for injury risks related to burn safety practices. For injury risks related to electrical burns, paraffin burns, and poisoning, a decline was also noted although this was not statistically significant. No decline was noted for fall-related risks.

Conclusions:

Subject to further replication and evaluation, home visits by paraprofessionals providing safety education, home inspection, and safety devices be considered for integration into a comprehensive child injury prevention strategy in low-income communities.
Association of smoking and smoking cessation with major causes of mortality in the Asia Pacific Region: the Asia Pacific Cohort Studies Collaboration
Authors: Barzi F , Huxley R , Jamrozik K , Lam T-H , Ueshima H , Gu D , Kim H C , Woodward M
Published: June 2008

Background:

Although the dangers of smoking, and the benefits of quitting, are well established and understood in the West, smoking remains popular among Asian men. We investigated the associations between smoking (including ex-smoking) and major causes of mortality in Asian men and women, and compared with Australians and New Zealanders (ANZ).

Methods:

An overview of 34 cohort studies in the Asia Pacific region involving 512 676 individuals (81 from Asia), followed up for a median of 6.7 years (20 804 deaths).

Results:

Mortality rates for cause-specific and all causes of mortality were systematically higher for current compared with never smokers. Hazard ratios (HR) for overall and cause-specific mortality comparing current-smokers with never smokers, ex- smokers with current-smokers and comparing numbers of cigarettes smoked per day, were higher for ANZ than Asia (p<0.001). For overall mortality, the HR (95 CI) comparing current-smoking with not was 1.37 (1.23 to 1.53) and 1.33 (1.26 to 1.40) in Asian men and women respectively. The corresponding figures in ANZ were 1.95 (1.81 to 2.09) and 1.85 (1.69 to 2.02). The HR for quitting in ANZ was 0.67 (0.63 to 0.71) and 0.66 (0.58 to 0.74) in men and women respectively. Quitting smoking had a significant benefit among Asian men, the HR was 0.88 (0.81 to 0.97) after ignoring the first 3 years of follow-up. There was no evidence of benefit for Asian women, for whom ex-smoking is rare.

Conclusions:

Allowing for the recent uptake of smoking in Asia, its effects are comparable to those observed in ANZ. Stringent tobacco control measures and smoking cessation strategies are urgently required in Asia.
SPECIATION AND NOMENCLATURE IN THE GENUS CELOSIA
Authors: Grant William F.
Published: June 2008

Guard cell measurements indicative of stomatal size were made on a number of herbarium specimens of cockscomb (C. cristata L., C. argentea var. cristata (L.) Ktze., et alii) and quail grass (C. argentea L.) in order to clarify further their taxonomic relationships. Cockscomb is considered by some authors to be synonymous with C. argentea L.; however, guard cell measurements averaged 9.59 and 11.70 units respectively, furnishing evidence for the distinctness of these two taxa. Consequently, cockscomb has been reinstated as C. CRISTATA L. In addition, five specimens were observed which possessed morphological characteristics of both C. cristata and C. argentea but were separable from both of these taxa by their guard cell measurements, which averaged 16.10 units. These plants collected in the Philippines and Central America are considered to have originated through hemialloploidy since the range of their guard cell measurements overlapped those of a known panalloploid between these species, namely, C. whiteii Grant. The geographic distribution of these plants indicates that hemialloploidy has occurred with a high frequency in the genus. A spontaneous fasciated plant has also been described which arose from seed of C. whiteii. Normal bivalent pairing of the chromosomes was observed in meiosis (n = 54) and progeny from this plant for three generations have all been fasciated.
The mode of action of helminthosporal. I. Effect on the formation of amylase by embryoless barley seeds
Authors: White G. A. , Taniguchi E.
Published: June 2008

Helminthosporal (H-al) is a phytotoxic sesquiterpenoid dialdehyde produced by the common root rot fungus, Bipolaris sorokiniana (Sacc. in Sorok.) Shoemaker. In addition to its phytotoxic properties, H-al can stimulate the synthesis of amylase and other proteins by embryoless barley seeds, having an optimum effect at a concentration of 0.1 mM. The monoacid derivative formed by air oxidation of H-al was only one-fourth as active as the dialdehyde. Helminthosporal and, particularly, the monoacid, can also inhibit the gibberellic acid (GA3) induced synthesis of amylase in barley half-seeds. The extent of inhibition was reduced when these compounds were added to half-seeds preincubated with GA3. The results of studies on the effect of H-al and its monoacid on the respiration of various plant tissues, including barley half-seeds, and on protein synthesis both in vivo and in vitro, have suggested that these substances inhibit amylase synthesis by blocking the supply of energy (ATP) in cells of the aleurone layer. Part of the inhibition may also involve the binding of the monoacid to a receptor site concerned in the mechanism of amylase induction by GA3. The hypothesis was tested that some type of relationship might exist between the inhibition of specific mitochondrial reactions and the induction of amylase synthesis. Among a wide variety of mitochondrial inhibitors only atractyligenin, amytal, and the lactone derivative of H-al could promote amylase synthesis. Amytal had high activity. The role of the mitochondrion in GA3-induced processes in the barley aleurone cell appears to warrant further investigation.
Fleurs pléiomères et synanthie chez Hyacinthus orientalis
Authors: Vieth Joachim
Published: June 2008

A score of pleiomerous flowers of Hyacinthus orientalis L. are described. About a quarter of these unquestionably result from synanthy. Morphology shows that, in some of the specimens, synanthy is caused by ontogenetic (postgenital) fusion. If a similar origin is admitted for certain nearly normal specimens encountered in this study, it would be another indication that the end product of synanthy may be an entity simulating a simple flower.
Factors affecting canker development on Populus tremuloides artificially inoculated with Hypoxylon pruinatum
Authors: Bagga Davinderjit K. , Smalley Eugene B.
Published: June 2008

A technique was devised for obtaining extensive canker development on wounded greenhouse-grown aspens (Populus tremuloides Mich.) inoculated with mycelium of Hypoxylon pruinatum (Klot.) Cke. Cankers developed rapidly only on water-stressed plants, and under such conditions often averaged 75 mm in length within 10 days. Alcohol treatment of stems before inoculation did not affect the course of canker development. Cankers developed most rapidly on plants watered every third or every fifth day, and developed least in plants watered daily. Stem wounds exposing the wood were essential for canker development. Wounds required an 8-day period before inoculation to heal sufficiently to inhibit canker development. Wound sites midway on the stem were most susceptible to canker development, while sites near the growing point were the least susceptible. Time for symptom appearance was prolonged in inoculated plants of larger diameters.
The distribution and ultrastructure of chloroplasts in leaves differing in photosynthetic carbon metabolism. II. Atriplex rosea and Atriplex hastata (Chenopodiaceae)
Authors: Downton W. J. S. , Bisalputra T. , Tregunna E. B.
Published: June 2008

Some aspects of chloroplast development for parenchymatic bundle sheath cells and mesophyll cells of Atriplex rosea leaves are described. The mesophyll chloroplasts begin to degenerate when the bundle sheath chloroplasts have reached a stage of maximum development. These events are related to the changing roles of the two types of chloroplasts in carbon dioxide assimilation. Leaves of Atriplex rosea are similar to those of tropical grasses in leaf anatomy, photosynthetic carbon metabolism, and CO2 compensation value. Atriplex hastata differs from A. rosea in leaf anatomy and is photosynthetically similar to the temperate grasses. There is a lack of parenchymatic sheath development and the chloroplasts which surround the vascular bundle are ultrastructurally identical with those in the rest of the mesophyll.
Conidium ontogeny in hyphomycetes. The annellophores of Scopulariopsis brevicaulis
Authors: Cole G. T. , Kendrick W. B.
Published: June 2008

The development of the annellophores and conidia of Scopulariopsis brevicaulis is traced in sequential photomicrographs; an interpretation of the process is given, and a detailed ontogenetic comparison is drawn between the annellophore and the phialide.
Annulate lamellae in spermatogenous cells of Lycopodium obscurum
Authors: Palisano John R. , Renzaglia Karen Sue , Maden Angel Renee , Whittier Dean P.
Published: June 2008

The existence of annulate lamellae is detailed for the first time in the ultrastructure of a plant flagellated cell lineage. In early spermatogenous cells of Lycopodium obscurum, annulate lamellae are abundant and located adjacent to either the nucleus or plastid. Individual organelles consist of 1–11 parallel cisternae bearing tightly compacted pores that are similar in size and substructure to nuclear pores. In cross section, the pores measure 95–130 nm in diameter. Frequently, endoplasmic reticulum is continuous with the annulate lamellae cisternae. The existence of annulate lamellae in Lycopodium extends the known distribution of these organelles to rapidly proliferating spermatogenous tissue of seedless plants. Moreover, spatial associations between annulate lamellae and plastids are reported for the first time in any plant tissue. Key words: Annulate lamellae, Lycopodium, plastid, "pteridophyte," spermatogenesis, ultrastructure.
Morphological contrasts between Hedysarum spinosissimum ssp. spinosissimum and ssp. capitatum warrant recognition of separate species
Authors: Baatout H.
Published: June 2008

The taxonomic status of the species complex Hedysarum spinosissimum L. (s.l.) has been evaluated on the basis of the phenetic variation within and between populations. Twenty-five characters were measured on plants grown from seeds of 9 populations of H. spinosissimum ssp. capitatum and 12 populations of H. spinosissimum ssp. spinosissimum from the western Mediterranean basin. Data were analyzed by means of multivariate methods. Stepwise discriminant analysis led to conclusions similar to those derived from principal components analysis. The results are discussed from a systematic point of view. On the basis of vegetative and floral characters, numerical analyses supported two morphologically distinct groups of operational taxonomic units corresponding to the predominantly selfing H. spinosissimum and the mostly outcrossing H. capitatum. Key words: Hedysarum spinosissimum L., phenetic variation, morphological contrast, Mediterranean basin, multivariate analysis.
Reexamination of six taxa described inLeptosphaeriafrom species in the Ranunculaceae
Authors: Ahn Young-mee , Shearer C. A.
Published: June 2008

Six fungal species previously placed in Leptosphaeria and originally described on plant species in the Ranunculaceae were reevaluated for their proper taxonomic position and redescribed and illustrated from the type and authentic materials. The original position of Leptosphaeria nigromaculata as Ophiobolus nigromaculata is confirmed. Metasphaeria rupicola is transferred to Massarina, and a lectotype is designated. Leptosphaeria scotophila and Leptosphaeria thorae are transferred to Phaeosphaeria, and a lectotype is designated for L. scotophila. The previous transfer of Leptosphaeria anthostomoides to Montagnula anthostomoides is confirmed. The new genus Barrella is established and typified by Leptosphaeria thalictri, and a neotype is designated. Key words: systematics, Loculoascomycetes, Leptosphaeria.
Effet du chlorure de sodium sur la composition lipidique de la feuille de colza (Brassica napus)
Authors: Najine Fouzia , Marzouk Brahim , Cherif Abdelkader
Published: June 2008

The effect of increasing NaCl concentrations up to 170 mM on the lipid composition of leaf membranes was studied on rape (Brassica napus L. var. oleifera Metzg) in hydroponic culture for one month. At NaCl concentrations lower than 102 mM, the polar glycerolipid biosynthesis was stimulated. NaCl concentrations higher than 102 mM reduced the contents in total lipids, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and phospholipids. In contrast, the neutral lipid contents increased with increasing NaCl concentration. An increase in NaCl induced a decrease in linolenic and hexadecatrienoic acid contents and an increase in linoleic and palmitic acid contents in all lipid groups. Key words: rape, lipids, sodium chloride.
A rose bengal amended medium for selecting nitrate-metabolism mutants from fungi
Authors: Elias Karol S. , Cotty Peter J.
Published: June 2008

A rose bengal amended medium for selecting nitrate-metabolism mutants from fungi with reduced sensitivity to chlorate is described. Isolates of several species known to resist development of nitrate-metabolism mutants on chlorate medium formed such mutants when grown on the rose bengal – chlorate medium. These species include Aspergillus flavus (Link.), Fusarium lateritium (Nees ex Link.), Fusarium oxysporum (Schlecht.), Fusarium solani (Mart.) Sacc., Alternaria cassiae (Jurair and Khan), Alternaria macrospora (Zimmerman), and Alternaria tagetica (Shome and Mustafee). The medium allows selection of nitrate-metabolism mutants of certain fungal strains for which chlorate-based techniques have not been satisfactory. Resulting mutants, following phenotype determination and identification of complementary testers, can be paired to enable macroscopic observation of heterokaryon formation during vegetative compatibility analyses. Thus, this medium may facilitate development of information on delimitation of vegetative compatibility groups among strains within these taxa. Key words: chlorate resistance, population structure, vegetative compatibility group, VCG.
Anisakis simplex (Nematoda: Anisakidae) Infection of the Musculature and Body Cavity of Atlantic Herring (Clupea harengus harengus)
Authors: McGladdery S. E.
Published: June 2008

The fillets and body cavities of the 305 Atlantic herring (Clupea harengus harengus) collected from six locations around the east coast of Canada were examined for Anisakis simplex larvae. The fillets were checked by candling over a fluorescent light and by digestion in a pepsin – HCl acid solution. The results demonstrated the inaccuracy of candling as a technique for detecting A. simplex larvae in the musculature of herring. Anisakis simplex larvae were found in the muscle of 7.9% of the herring examined, and all herring with fillet infections were from one sample collected from southern Newfoundland in February 1983. All had over 15 larvae in the body cavity. Since none of the other herring examined had over eight larvae in the body cavity, I concluded that most Canadian Atlantic herring are safe for consumption raw, salted, smoked, or pickled. The results from Canadian Atlantic herring were compared with those from herring collected by Smith and Wootten from around Britain. The only Canadian Atlantic herring found with a similar level of infection to those were from southern Newfoundland.
A Robust Approach to Equilibrium Yield Curves
Authors: Walter Gilbert G.
Published: June 2008

The surplus yield models of fisheries management usually assume that a concave function of equilibrium yield versus fishing effort exists. However, this function is notoriously difficult to fit to real data for a number of reasons, including the fact that few fisheries are in equilibrium. A procedure for obtaining rough estimates of these equilibrium curves is introduced. Management strategies based on these estimates and the annual yield curves are also presented. The procedures are then applied to several fish stocks.
Comparison of Acoustic Population Estimates of Salmon in a Lake with a Weir Count
Authors: Mulligan T. J. , Kieser R.
Published: June 2008

Acoustic population estimates are performed routinely in fisheries. Usually, however, they have to stand on their own merit. A unique opportunity has been exploited to compare a series of acoustic surveys with a weir count that monitors the escapement of sockeye salmon, Oncorhynchus nerka, into a lake. Each survey was analysed by three acoustic methods; the results are compared among themselves and with the weir count. A detailed sensitivity analysis looks at the possible variance and bias in each method. Finally, several methods are used to estimate the acoustic fish target strength. These estimates are compared with published target strength values.
Comparative Life History Characteristics of Hatchery and Wild Steelhead Trout (Salmo gairdneri) of Summer and Winter Races in the Kalama River, Washington
Authors: Leider Steven A. , Chilcote Mark W. , Loch John J.
Published: June 2008

Life history information was collected from adult upstream migrant hatchery and wild steelhead trout (Salmo gairdneri) of summer-run and winter-run racial origin in the Kalama River, Washington, from 1976 to 1984. We found inter- and intraracial distinctions among many of the characteristics examined. In contrast with winter steelhead, summer steelhead generally had a temporally protracted time of return, fewer total age categories, fewer repeat spawners, and greater size at a given marine age. Compared with wild steelhead, hatchery steelhead generally had fewer saltwater age categories and a lower incidence of respawners. Based on differences in return timing, age composition, and size at maturity, we suggest that greater similarities currently exist between Kalama River hatchery and wild summer steelhead than between hatchery and wild winter steelhead.
Patterns in the Composition of Arctic Tundra Pond Microcrustacean Communities
Authors: Hebert Paul D. N. , Hann Brenda J.
Published: June 2008

On the basis of intensive collections of Microcrustacea (Cladocera, Copepoda, Anostraca, and Notostraca) from 11 sites in the Canadian arctic archipelago, patterns of species richness, distribution, and community composition were evaluated. Microcrustacean communities of pond habitats in the high arctic of Canada are much less diverse than communities at more mesic, subarctic sites. There is both a marked decline in species richness and a dramatic change in the composition of pond communities with increasing latitude and decreasing summer temperatures. Ponds in the low arctic have 3–4 times as many species as those in the high arctic and are dominated by calanoid copepods, a group largely absent from the high arctic. Sites with similar climatic conditions in Alaska have microcrustacean communities with higher species richness, a phenomenon correlated partially with the presence of glacial refuges throughout the Pleistocene. The failure of certain zooplankton taxa, especially calanoids, to colonize areas in the Canadian arctic remote from refuges in the 7000 yr since deglaciation suggests that their dispersal rates are low. Reestablishment of complete zooplankton communities in glaciated terrain with severe environmental conditions apparently requires long periods, although initial colonization by a few pioneer species may be rapid.
Growth of the Vasa Deferentia of Mature Homarus americanus: Conflicting Results from Field and Laboratory Studies
Authors: Aiken D. E. , Waddy S. L.
Published: June 2008

Successive samples from mature and maturing male Homarus americanus from the Gulf of St. Lawrence indicated that the vasa deferentia grow rapidly in spring and then regress. Growth of the vasa deferentia was followed in the laboratory in this same stock of lobsters by surgically removing first one and then the other of the paired vasa deferentia during the year. The laboratory study indicated that vas deferens weight, which increases nearly 50% during May and June, continues to increase through autumn and winter at a reduced rate consistent with normal somatic growth. There was no evidence of regression, and no support for an hypothesis of cyclic seasonal change associated with mating activity. The regression suggested by the field study appears to be the effect of ecdysis, which abruptly alters the relationship between animal size and organ size.
Identification and characterization of a unique cysteine residue proximal to the catalytic site of Arabidopsis thaliana carotenoid cleavage enzyme 1
Authors: Guo Shukui , Boyd Jason , Sammynaiken Ramaswami , Loewen Michèle C.
Published: June 2008

AtCCD1 and AtNCED3 are related carotenoid cleavage enzymes from Arabidopsis thaliana that catalyze the oxidative cleavage of, respectively, the 9,10 (9′,10′) double bonds of carotenoid substrates such as β-carotene, and the 11,12 double bond of 9-cis epoxycarotenoids. Although the cellular and cleavage functionalities of these enzymes have been reported, their mechanisms and related structural environments mediating these disparate specificities in homologous enzymes have not been well characterized. By relating the differences observed in UV and visible light absorption and Cu(II) electron paramagnetic signals to variations in sequence alignments and 3-D homology models of the two A. thaliana enzymes, we identified a putatively proximal cysteine residue (Cys352) in AtCCD1 that is not conserved in AtNCED3. Spectral analysis of the Cys to Ala mutant confirmed its uniqueness and proximity to the metal binding site, but precluded any role for the residue in the mediation of the observed metal binding affinity or associated steric constraint differences. Further analysis of kinetic substrate cleavage properties indicated a decrease in Vmaxand a subtle increase in Kmfor the C352A mutant compared with those observed for the wild-type, thus confirming catalytic site proximity and suggesting possible roles for the unique cysteine in the modulation of substrate affinity and (or) the reaction rate of AtCCD1.
Relative efficiency and reliability of parametric and nonparametric sequential accuracy testing plans
Authors: Wang Yue , LeMay Valerie M. , Marshall Peter L.
Published: June 2008

The relative efficiency and reliability of parametric and nonparametric sequential accuracy testing plans were investigated using Monte Carlo techniques with normal and non-normal distribution generators. For the normal distributions, zero (no equation bias) and nonzero (some equation bias) means were simulated. For normal distributions with a nonzero mean, a modified nonparametric testing plan was developed and compared with the bias-free parametric test. The parametric testing plans resulted in average sample numbers to reach a terminal decision that were 20–40% smaller than the nonparametric testing plans, when the prediction errors of a model were normally distributed. In this circumstance, both the parametric and nonparametric testing plans yielded actual probabilities of making a type I or II error close to the nominal values, with the parametric testing plans giving somewhat lower error probabilities. When model errors followed a non-normal distribution, the nonparametric testing plans still resulted in error probabilities close to the nominal values, but this was not the case for the parametric testing plans.
Evaluating insect-mediated dispersal of Scytalidiumuredinicola for biological control of western gall rust
Authors: Currie Cameron R. , Hiratsuka Yasu
Published: June 2008

The potential for augmentative biological control of western gall rust, caused by Endocronartiumharknessii (J.P. Moore) Y. Hiratsuka, on lodgepole pine (Pinuscontorta Dougl. var. latifolia Engelm.) was investigated near Hinton, Alberta. We sought to determine whether a mycoparasite, Scytalidiumuredinicola Kuhlman et al., of western gall rust could be enhanced through releases of a beetle, Epuraeaobliquus Hatch, which can serve as a vector for the mycoparasite. Mycoparasites parasitized increasing proportions of the sporulating tissue on older galls, so that most galls 10 years or older had more than 95% of their sporulating surface parasitized. Scytalidiumuredinicola was the most common mycoparasite in the sporulating tissue of western gall rust, was present early in the season, and appeared to overwinter inside the tissue of the gall. Adults and larvae of E. obliquus were important in spreading the mycoparasite across the surface of galls, especially on galls younger than 10 years. From a mark recapture experiment and sticky-trap sampling, it was determined that E. obliquus is strongly attracted to western gall rust and therefore is a promising candidate to disseminate the mycoparasite. In a small-scale release experiment, beetles inoculated with S. uredinicola did not successfully initiate significant numbers of infections. However, of the few infections initiated under experimental conditions, all occurred in the treatment providing beetle access.
Physiological, structural, and nutritional parameters of Norway spruce needles from declining forest stands in Austria
Authors: Tausz Michael , Zellnig Günther , Bermadinger-Stabentheiner Edith , Grill Dieter , Katzensteiner Klaus , Glatzel Gerhard
Published: June 2008

Decline phenomena in two spruce (Piceaabies (L.) Karst.) forests in different locations in Austria are described on a biochemical and ultrastructural level. Needles of declining trees (canopy state class 3 or 4, more than 40% needle loss, and visible needle chlorosis) are characterized by loss in chlorophylls, xanthophylls, and carotenes in older needles, with α-carotene and chlorophyll a showing strongest depressions. Total chlorophyll concentrations in visibly yellowed needles range below 1 mg•g−1 dry weight, whereas green needles contain more chlorophyll. All trees included in this study fit in one common model with respect to the pigment changes, suggesting that needle yellowing is a consequence of secondary reactions rather than an initial state of decline. Depressed α-carotene/β-carotene ratios are associated with electron-microscopically visible thylakoid reductions, and needles with lightened plastoglobuli exhibited higher neoxanthin contents. Apparently healthy trees (canopy state class 1 or 2, less than 40% needle loss) in the declining stands were used to correlate nutrient status and antioxidant responses (glutathione and ascorbic acid concentrations), respectively, versus chlorophyll contents to reveal primary contributors to decline symptoms. At one of the investigated sites chlorophyll concentrations are significantly correlated to nitrogen, calcium, and potassium contents of the needles. At the second site, correlations of glutathione levels to chlorophyll concentrations point to a considerable contribution of oxidative stresses to decline symptoms of the spruce stands in the second location, where nutritional factors do not seem to play a dominant role in the initial stages of the needle yellowing.
Effect of aluminum on growth of newly germinated and 1-year-old red spruce (Picearubens) seedlings
Authors: Schier George A.
Published: June 2008

Effects of Al on the growth of newly germinated and 1-year-old red spruce (Picearubens Sarg.) seedlings were compared by growing seedlings for 13 weeks in sand irrigated with nutrient solution (pH 3.8) containing 0, 5, 10, 20, 40, and 80 mg/L Al. Compared with controls, roots of newly germinated seedlings produced significantly less biomass across all Al levels tested and had a lower Al toxicity threshold than roots of 1-year-old seedlings. Although the mean relative effects of Al on needle and stem dry weights of the two age-classes were not significantly different, reductions in shoot biomass at low Al levels were greater in 1-year-old than in newly germinated seedlings. However, at high levels, shoots of newly germinated seedlings showed greater sensitivity to Al. Foliar concentrations of Al were significantly higher and P concentrations were significantly lower in 1-year-old than in newly germinated seedlings.
Effects of long-term prescribed burning on the activity of select soil enzymes in an oak–hickory forest
Authors: Eivazi F. , Bayan M.R.
Published: June 2008

In low-input or unmanaged ecosystems, the relationship between soil enzyme activity and plant biomass is expected and may be used as an early and sensitive indicator of soil productivity. This study was designed to (1) examine the long-term effects of burning on the activities of arylsulfatase, acid phosphatase, α- and β-glucosidase, and urease; (2) determine the relationship between microbial biomass C and enzyme activities as affected by long-term prescribed burning; and (3) study the seasonal variations in activities of the above-mentioned enzymes. Soil samples (Typic Fragiudalf) were collected from southeastern Missouri where a long-term burning experiment was established in 1949. Treatments consisted of (1) annual burning; (2) periodic burning, every 4 years; and (3) control, unburned. Soil samples (0–15 cm) were collected before and after annual and periodic burning during 1992 and seasonally in 1993. Long-term burning treatments significantly reduced the activities of enzymes studied but did not affect the pH and organic C. The microbial biomass C, total N, available P, and available S content of soil samples from both annual and periodic burning plots were significantly reduced. A significant positive correlation between soil enzyme activities and the microbial biomass was established. The treatment effects were apparent over the background seasonal variability, with reduced enzyme activity for the annual and periodic burning plots as compared with the unburned plots.
The effect of a continuous springtime fumigation with SO2 on CO2 uptake and structure of the annual ring in spruce
Authors: Keller T.
Published: June 2008

Potted grafts of old spruces (Piceaabies (L.) Karst.) were continuously fumigated with SO2 (contro1, 0.05, 0.1, and 0.2 ppm) in outdoor fumigation chambers. SO2 concentrations were maintained for 10 weeks from late in April till early in July 1976. CO2 uptake was measured periodically under standardized laboratory conditions with an infrared gas analyzer. After fumigation, the plants remained in the nursery till November 1977. Afterwards, stem slices were taken for X-ray measurements of both ring width and wood density. An arbitrary density of 0.5 g cm−3 was chosen to distinguish early wood from late wood. CO2 uptake was depressed significantly before visible symptoms of injury appeared. The relative CO2 uptake in the 7th to 10th week of fumigation and the number of cells in a radial file of the annual ring were well correlated. With increasing SO2 concentration, the width of the annual ring decreased. The amount and density of late wood was reduced by a springtime fumigation. A distinct decline of wood production with increasing SO2 concentration was also found in cases where no visible injury occurred.
Pressure–volume curves of shoots and roots of normal and drought conditioned western hemlock seedlings
Authors: Kandiko R. A. , Timmis R. , Worrall J.
Published: June 2008

Pressure–volume curves for western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings showed roots to have lower osmotic potentials, at both full turgor and incipient plasmolysis, and lower relative water contents at incipient plasmolysis than shoots. Roots remained turgid under mild water deficit, whereas shoots lost turgor exponentially with water content. Shoots of seedlings given a 2-week drought stress had lower osmotic potentials at full turgor and incipient plasmolysis than shoots of unstressed seedlings; roots showed a similar trend.
Differential response of paper birch provenances to aluminum in solution culture
Authors: Steiner K. C. , McCormick L. H. , Canavera D. S.
Published: June 2008

Progenies belonging to 49 open-pollinated families of paper birch (Betulapapyrifera Marsh.) representing 13 provenances were evaluated sequentially for rate of root elongation in solutions containing only calcium nitrate and solutions containing calcium nitrate + 120 ppm aluminum. Provenances, but not families within provenances, differed significantly in both rate of root elongation and apparent response to Al. Provenance mean tolerance indices (root growth in Al solutions/root growth in non-Al solutions) varied from 0.10 to 0.37. Exposure to 120 ppm Al caused decreased concentrations of Ca and Cu in the foliage, decreased or nearly unchanged concentrations of P and Mg, and increased concentrations of Al, B, and Mn. Compared with the more tolerant provenances, intolerant provenances exhibited generally greater increases in foliar Al concentration after exposure to Al. Differential tolerance to Al will be useful in improving the performance of planted trees on Al-toxic sites.
Effect of SO2 on transpiration, chlorophyll content, growth, and injury in young seedlings of woody angiosperms
Authors: Suwannapinunt W. , Kozlowski T. T.
Published: June 2008

Effects of SO2 on transpiration, chlorophyll content, growth, and injury of woody angiosperm seedlings were studied during the first few weeks after germination. Fumigation of silver maple (Acersaccharinum L.) and black locust (Robiniapseudoacacia L.) seedlings with SO2 at 0.75 ppm for 2 to 16 h increased transpirational water loss. As duration of fumigation was increased, the effect of SO2 on increasing transpiration declined. Leaves of silver maple seedlings fumigated with SO2 at 0.75 ppm for 8 to 16 h were injured; those of black locust were not. In another experiment, the adverse effects of SO2 were greater on black locust than on American elm (Ulmusamericana L.) seedlings. Fumigation of young black locust seedlings with SO2 at 2 ppm for 1 or 4 h significantly reduced chlorophyll content, height growth, dry weight increment of roots, and leaf formation. Leaf injury symptoms appeared within 24 h after fumigation with 2 ppm SO2 for 4 h. Fumigation of American elm seedlings with SO2 at 0.5 or 2 ppm for 0.5 to 4 h decreased dry weight increment of roots but did not injure plants or significantly influence chlorophyll content, height growth, or leaf dry weight. Inhibition of dry weight increment of roots was a more sensitive indicator of susceptibility to SO2 than was reduction in dry weight increment of shoots.
Estimating phloem thickness in lodgepole pine stands using electrical resistance measurements
Authors: Cole D.M. , Jensen C. E.
Published: June 2008

Correlations among measurements of electrical resistance of cambial zone tissue, phloem thickness, and tree diameter, reported earlier for other species, were also found for lodgepole pine (Pinusconforta Dougl.). Using these relationships, a model was developed for estimating phloem thickness in lodgepole pine, an important factor in assessing stand susceptibility to mountain pine beetle (Dendroctonusponderosae Hopk.) epidemics. The predictive model and procedures for scaling estimates to specific time and location were tested with data from a lodgepole pine stand nearly 100 miles (161 km) away from the sample trees used in fitting the model. Results for stand data grouped into 3-in. (7.6 cm) diameter classes showed that class means of scaled model estimates were within ±4% of class means of phloem thickness for all diameter classes of the test stand. Model development and application procedures should be applicable to other species where estimates of phloem thickness and its distribution in stands is of interest.
Estimating the solid-wood content of stacked logs with minimum total cost
Authors: Smith Victor G.
Published: June 2008

not available
Effect of defoliation on transpiration in grand fir
Authors: Lopushinsky W. , Klock G. O.
Published: June 2008

Heat pulse velocity was monitored in large grand fir (Abiesgrandis (Dougl.) Lindl.) trees before and after defoliation brought about by aerial spraying with Paraquat. Heat pulse velocity of trees which later became severely defoliated declined rapidly after mid-July to near base values in early September. Heat pulse velocity in mid-August was only 27% of the seasonal maximum rate compared with an expected rate of 70%. Heat pulse velocity in partially defoliated and unsprayed trees declined gradually, reaching minimum values in November.
The potential of Weibull-type functions as flexible growth curves: reply
Authors: Kozak A. , Smith J. H. G.
Published: June 2008

not available
Evaluation of beetle-killed white spruce for pulp and paper
Authors: Werner Richard A. , Elert Erwin E. , Holsten Edward H.
Published: June 2008

A kraft pulping study on standing white spruce (Piceaglauca (Moench) Voss) killed by spruce beetles (Dendroetonusrufipennis (Kirby)) in south central Alaska showed no difference in pulp yield between trees dead for 1 year and those dead for as long as 50 years. Strength properties of beetle-killed white spruce remained extremely high in all dead trees regardless of how long they had been dead, so they apparently could be used for producing high-quality kraft pulps. These are the first results reported in which standing trees dead for as long as 50 years produced high-quality bleached and unbleached pulps.
Fifth-year height variation in western hemlock open-pollinated families growing on four test sites
Authors: Foster G. S. , Lester D. T.
Published: June 2008

Fifth-year total height was analyzed for 213 open-pollinated families of western hemlock (Tsugaheterophylla (Raf.) Sarg.) growing at one or more test sites. Significant variation was found among sites and among families. For 87 families represented at each of four sites, heritability of family means for 5-year height was estimated as 0.57. Estimated genetic gain was 11% from selecting the top 10% of the families. Site × family interaction was nonsignificant.
Crown structure of a codominant Douglas-fir
Authors: Jensen Edward C. , Long James N.
Published: June 2008

Results are presented from an intensive study of crown structure in a 39-year-old codominant Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco). The patterns of crown development observed may represent a species adaptation for maximizing photosynthetic efficiency. While branches originating at nodes provide the basic structure of the crown, short-lived nonnodal branches provide much of the photosynthetic capacity. In addition, nonnodal branches support nearly half of the young needles near the top and outside edges of the crown.
Comparing biomass regressions by site and stand age for red maple
Authors: Crow T. R.
Published: June 2008

Allometric regressions for estimating red maple (Acerrubrum L.) biomass did not differ by stand age and site index. Significant differences were found only in terms of error variance, not in terms of regression slope or intercept. These trends suggest a single predictive model is valid for regional estimates. More attention should be given to regional sampling procedures and predictive relations that are valid for a wide range of stand and site conditions in developing weight tables and conducting biomass inventories.
Estimation of stand basal area growth and yield with a reverse logistic function
Authors: Sadiq Riyaz A.
Published: June 2008

Logistic curves have been used to study the growth of human and animal populations. Physical chemists have used it to study the growth and senescence of chemical reactions. The present study investigates the application of the curve to forest stands for estimating basal area growth and yield. Graphic analysis with the basal area growth data, from permanent sample plots in red pine (Pinusresinosa Ait.) plantations of southern Ontario, exhibited reverse logistic trends. The parameters of the reverse logistic function were estimated by nonlinear regression techniques. Freese's chi-square test was employed to determine the accuracy of the resulting estimates of basal area growth and yield. Results, from the data used here, indicate that the function not only fits the data well but also has high predictive power.
Intensification and lateral spread of Arceuthobiumlaricis in a young stand of western larch with stocking control
Authors: Wicker Ed F. , Wells James M.
Published: June 2008

Initial intensification and lateral spread of Arceuthobiumlaricis (Piper) St. John were measured for three levels of stocking, 1680, 549, and 272 stems/ha (2.4 × 2.4, 4.3 × 4.3, and 6.0 × 6.0 m spacing) of young, single-layer, western larch (Larixoccidentalis Nutt.) monoculture, following artificial inoculation. Intensification was slow for the first 6 years following inoculation, but showed 5- to 10-fold increases in treatment means for the next 3-year period. Lateral spread from the inoculated trees to neighboring suscepts was not observed during the first 6 years, but was observed in all three treatments between years 7 and 9 and averaged 3.5–4.9 m for the three spacing treatments. Maximum lateral spread during the period was 6.4 m. We conclude that A. laricis can intensify rapidly on young western larch once an inoculum source is established. The lowest stocking level (highest spacing level, 6 × 6 m) used in this study did not prevent lateral spread of the pathogen. These data attest to the value of prevention or early detection and removal of infections for the protection of western larch stands from subsequent losses.
Growth and water relations of black locust and pine seedlings exposed to controlled water stress
Authors: Schulte Paul J. , Marshall Paul E.
Published: June 2008

Some responses of very young jack pine (Pinusbanksiana Lamb.), red pine (Pinusresinosa Ait.), and black locust (Robiniapseudoacacia L.) seedlings grown under constant water stress conditions induced by polyethylene glycol 4000 culture solutions were investigated. Seedlings grown under stressful conditions had lower leaf conductance, produced less foliar surface area, and accumulated less dry weight than nonstressed seedlings. Seedlings grown under nonstressed conditions were found to undergo considerable transpiration at night. When compared with the pines, black locust seedlings grew more rapidly, had lower (more negative) xylem pressure potentials, and showed poorer survival under the more stressful growth conditions.
Response of tree roots to decomposing organic matter in two lowland Amazonian rain forests
Authors: John T. V. St.
Published: June 2008

Fine roots of tropical rain forests are sometimes associated with decomposing organic matter at the soil surface. This association is considered by some authors to be important in recovery of nutrients by the vegetation. In this paper, experimental evidence is presented to show that the association results from a dynamic process and is not a coincidental result of negative geotropism. The association appears to be the result of random encounters of growing roots with organic matter, followed by increased branching at that site. The concentration of absorbing tissue in such relatively nutrient-rich sites as decomposing organic matter implies more effective ion absorbtion than would result if roots were randomly distributed in the soil volume.
Cortical resin monoterpenes in Sitka spruce and resistance to the white pine weevil, Pissodesstrobi (Coleoptera: Curculionidae)
Authors: Harris L. J. , Borden J. H. , Pierce Jr. H. D. , Oehlschlager A. C.
Published: June 2008

To determine whether monoterpene content of Sitka spruce, Piceasitchensis (Bong.) Carr., could be correlated with resistance to the white pine weevil, Pissodesstrobi Peck, the relative amounts of cortical monoterpenes of five 50-year-old resistant and five susceptible trees of the same age were analyzed. The resistant Sitka spruce had significantly lower β-phellandrene and higher β-pinene and 3-carene content than the susceptible trees. This monoterpene profile could be used as an indicator of resistant trees.
Xylem nitrogen as a possible diagnostic nitrogen test for loblolly pine
Authors: Cotrufo Cosimo
Published: June 2008

Radial stem wood sections of fertilized (at age 14 years) and unfertilized loblolly pine (Pinustaecla L.) trees were analyzed 5 and 9 years after treatment to establish if xylem nitrogen (N) can be used for a diagnostic nitrogen test. The percentage of xylem nitrogen in wood formed since fertilization was greater in fertilized than in unfertilized trees. The 2 years of wood growth near the cambium had a higher percent N than older wood, but differences between treatments were less pronounced than in older wood. Concentrations of N for fertilized and unfertilized trees were nearly constant for 2- to 9-year-old wood indicating that a sampling technique to determine the N status of loblolly pine could be developed by increment coring.