bluuebunny/crossref_metadata_2025 huggingface dataset:
Breastfeeding outcomes for mothers with and without home access to e‐technologies
Authors: Laborde Laurent , Gelbert‐Baudino Nathalie , Fulcheri Julie , Schelstraete Camille , Francois Patrice , Labarere Jose
Published: May 2008

Aim: To estimate the percentage of breastfeeding mothers with home access to e‐technologies and to compare breastfeeding outcomes for mothers with and without access to e‐technologies.

Methods: We conducted a prospective observational study of 550 breastfeeding mothers discharged from nine maternity units in France.

Results: Overall, 435 mothers (79%; 95% confidence interval [95% CI], 75–82) had home access to e‐technologies. Mothers with access to e‐technologies were less likely to be unemployed (6% vs. 15%, p = 0.004), to smoke during pregnancy (8% vs. 16%, p = 0.03), to have a breastfeeding assessment score <8 (39% vs. 59%, p < 0.001) and to use a pacifier (23% vs. 41%, p < 0.001). Although mothers with access to e‐technologies had a longer median breastfeeding duration than those without home access to e‐technologies (19 vs. 16 weeks, p = 0.02), adjusted hazard ratios for breastfeeding discontinuation (0.85; 95% CI, 0.60–1.21), overall satisfaction rates (73% vs. 67%, p = 0.19) and breastfeeding difficulties after discharge (58% vs. 61%, p = 0.60) were not different for the two groups.

Conclusion: A vast majority of breastfeeding mothers have home access to e‐technologies in France. However, access to e‐technologies was not independently associated with better breastfeeding outcomes in this study.
Comparison of self‐reported emotional and behavioural problems in adolescents from Greece and Finland
Authors: Kapi Aikaterini , Veltsista Alexandra , Sovio Ulla , Järvelin Marjo‐Riitta , Bakoula Chryssa
Published: May 2008

Aim: To compare self‐reported emotional and behavioural problems among Greek and Finnish adolescents.

Methods: Youth Self‐Report scores were analysed for 3373 Greek adolescents aged 18 years and 7039 Finnish adolescents aged 15–16 years from the general population in both countries. The impact of country, gender, place of residence, socioeconomic status (SES) and family stability on the scores was evaluated.

Results: Only country and gender yielded small to medium effect on the scores. Greek boys scored significantly higher than Finns on 10 of the 11 YSR syndromes, particularly on the anxious/depressed scale. Greek girls scored significantly lower than Finnish girls on the somatic complaints and delinquent behaviour scales. In general, girls scored higher than boys on both internalising and externalising problems. The gender by country interaction revealed that Finnish girls reported more externalising problems.

Conclusion: The main differences marked in this comparison were the higher level of anxiety and depression in Greeks than Finns and the higher level of externalising problems in Finnish girls than boys. Cultural standards could play an important role in explaining these differences. Overall, it seems that only a small number of differences exist between a northern and southern European region.
Nonfatal congenital alveolar dysplasia due to abnormalities of NO synthase isoforms
Authors: Hegde S , Pomplun S , Hannam S , Greenough A
Published: May 2008

Congenital alveolar dysplasia (CAD) is a rare disorder thought to represent alveolar growth arrest at the canalicular stage of development. An infant with CAD diagnosed on lung biopsy is reported, her respiratory problems resolved spontaneously and she was doing well at follow‐up. The infant additionally suffered from systemic hypertension and hypertrophic pyloric stenosis.

In conclusion, we speculate that the association of CAD with systemic hypertension and hypertrophic pyloric stenosis might be explained by abnormalities of isoforms of nitric oxide synthase (NOS) resulting in congenital deformities involving smooth muscles.
Nonalcoholic fatty liver disease in overweight children and adolescents
Authors: Sagi R , Reif S , Neuman G , Webb M , Phillip M , Shalitin S
Published: May 2008

Objective: To investigate the prevalence and characteristics of non‐alcoholic fatty liver disease (NAFLD) and identify predictors for NAFLD in an overweight paediatric population.

Methods: The study group included 58 overweight (BMI‐SDS 3.37 ± 1) patients aged 8–18 years attending the paediatric obesity clinic. They underwent a clinical and biochemical work‐up and liver ultrasonography. Grading of liver steatosis severity was done according to discrepancy in ultrasonographic liver‐kidney densities.

Results: The prevalence of NAFLD was 60.3%. There was a highly significant (p = 0.004) association between severity of obesity and the presence or absence of liver steatosis.

The study cohort was divided into three groups: group 1 (patients with normal ultrasonographic liver structure and normal liver enzymes), group 2 (patients with ultrasonographic fatty liver and normal liver enzymes) and group 3 (patients with ultrasonographic fatty liver and elevated liver enzymes).

The BMI‐SDS was significantly higher in group 3 compared to group 1 (4.2 ± 1.1 vs. 2.8 ± 0.9, p < 0.001). The rate of obesity complications was more prevalent in group 3 compared to groups 1 and 2 (p < 0.001). The insulin resistance index was higher in group 3 compared to group 1 (0.75 ± 0.2 vs. 0.47 ± 0.3, p < 0.05).

Conclusions: The prevalence of NAFLD in our study cohort was high (60.3%). Patients with steatosis and elevated liver enzymes had a higher risk for obesity complications. Measurements of liver enzymes alone are insufficient, and liver ultrasonography is required for early identification of NAFLD.
Early amplitude‐integrated EEG correlates with cord TNF‐α and brain injury in very preterm infants
Authors: Wikström Sverre , Ley David , Hansen‐Pupp Ingrid , Rosén Ingmar , Hellström‐Westas Lena
Published: May 2008

Aim: To investigate if the early electroencephalogram (EEG) and amplitude‐integrated EEG (aEEG) in very preterm infants is affected by perinatal inflammation and brain injury, and correlates with long‐term outcome.

Methods: Sixteen infants born at 24–28 gestational weeks (median 25.5) had continuous EEG/aEEG during the first 72 h of life. Minimum and maximum EEG interburst intervals (IBI), and aEEG amplitudes were semi‐automatically quantified and averaged over the recording period. Neonatal brain injury was diagnosed with repeated cranial ultrasound investigations. Nine cytokines from four time‐points were analyzed during the first 72 h (umbilical cord blood, 6, 24 and 72 h), and outcome was assessed at 2 years of corrected age.

Results: Infants with neonatal brain injury (n = 9) had prolonged IBI, 11.8 (9.6–23.2) sec versus 8.2 (7.1–11.6) sec in infants (n = 7) without brain damage (p = 0.005). Handicap at 2 years (n = 8, including two infants without neonatally diagnosed brain injury) was associated with prolonged neonatal IBI and lower aEEG amplitudes. Also aEEG amplitudes were decreased in infants with neonatal brain injury. There was a significant positive correlation between the averaged IBI and cord blood TNF‐α (rs = 0.595, p = 0.025).

Conclusion: Early EEG depression is associated with increased cord blood TNF‐α, neonatal brain damage and handicap at 2 years.
Patterned orocutaneous therapy improves sucking and oral feeding in preterm infants
Authors: Poore M , Zimmerman E , Barlow SM , Wang J , Gu F
Published: May 2008

Aim: To determine whether NTrainer patterned orocutaneous therapy affects preterm infants' non‐nutritive suck and/or oral feeding success.

Subjects: Thirty‐one preterm infants (mean gestational age 29.3 weeks) who demonstrated minimal non‐nutritive suck output and delayed transition to oral feeds at 34 weeks post‐menstrual age.

Intervention: NTrainer treatment was provided to 21 infants. The NTrainer promotes non‐nutritive suck output by providing patterned orocutaneous stimulation through a silicone pacifier that mimics the temporal organization of suck.

Method: Infants' non‐nutritive suck pressure signals were digitized in the NICU before and after NTrainer therapy and compared to matched controls. Non‐nutritive suck motor pattern stability was calculated based on infants' time‐ and amplitude‐normalized digital suck pressure signals, producing a single value termed the Non‐Nutritive Suck Spatiotemporal Index. Percent oral feeding was the other outcome of interest, and revealed the NTrainer's ability to advance the infant from gavage to oral feeding.

Results: Multilevel regression analyses revealed that treated infants manifest a disproportionate increase in suck pattern stability and percent oral feeding, beyond that attributed to maturational effects alone.

Conclusion: The NTrainer patterned orocutaneous therapy effectively accelerates non‐nutritive suck development and oral feeding success in preterm infants who are at risk for oromotor dysfunction.
Investigating the Effects of High-Dose Phenylephrine in the Management of Prolonged Ischaemic Priapism
Authors: Muneer Asif , Minhas Suks , Freeman Alex , Kumar Pardeep , Ralph David J.
Published: May 2008

Introduction

Acute priapism can be managed by corporal blood aspirations and the instillation of α adrenergic agonists such as phenylephrine if patients present early. Following prolonged ischaemic priapism, this regimen is often unsuccessful, and the use of phenylephrine is limited due to systemic cardiovascular side effects.

Aim

To investigate the effects of high-dose phenylephrine on human corpus cavernosal smooth muscle obtained from patients presenting with refractory ischaemic priapism.

Methods

Strips of corpus cavernosum were obtained from six patients presenting with prolonged ischaemic priapism (duration 60–240 hours), where detumescence was refractory to conventional doses of phenylephrine. The smooth muscle contractile response to high doses of phenylephrine were then compared with that of normal control corpus cavernosum obtained from four patients undergoing a penectomy for penile cancer. The tissue was then analyzed using TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling) to assess its viability.

Main Outcome Measures

The in vitro response to high-dose phenylephrine of corpus cavernosum smooth muscle obtained from patients with refractory priapism compared with normal human corpus cavernosum.

Results

Corporal blood gas analysis confirmed hypoxia (pO2 1.5–2.3 kPa), acidosis (pH 6.9–7.1), and glucopenia (0–0.3 mmol/L) in all six patients confirming the ischaemic nature of the priapism. Application of high doses of phenylephrine produced a marked muscle contraction in the control tissue, but there was no contractile response at all in any of the priapism patients. Analysis with TUNEL indicated widespread smooth muscle cell apoptosis in all the priapism tissue.

Conclusions

This study has shown that patients with ischaemic priapism that fails to respond to conventional doses of an α-agonist are unlikely to benefit from continual or high-dose phenylephrine administration, as there is usually widespread apoptosis of the cavernosal smooth muscle preventing further contraction.
Seeding rate for the sorghum‐sudangrass hybrid (Sorghum bicolor Moench × Sorghum sudanense [Piper] Stapf.) in the mixed seeding cultivation with corn (Zea mays L.) under a partial tillage condition in Kyushu region, Japan
Authors: Kobayashi Ryoji , Sato Kenzi , Hattori Ikuo , Tateno Koji
Published: May 2008

In the Kyushu region of Japan, mixed seeding cultivation of corn and sorghum is promising as a labor‐saving cropping system that makes effective use of forage crop fields in the summer season. In this study, we tested a few levels of seeding rates of a sorghum‐sudangrass hybrid (SSH) in a mixed seeding with corn planted at the standard rate (6.67 plants m−2) under a partial tillage condition in fields where Italian ryegrass had been sown after manure application and its second crop had been harvested. Our results indicate that the appropriate seeding rate of SSH with corn under partial tillage to maximize both the corn yield in the first crop and the annual yield is 1 g m−2, irrespective of the manure application levels. At this rate, the annual yield from the mixed‐seeded plots of corn and SSH was 20% higher than that from plots on which corn was seeded alone.
BIOCHEMISTRY CHARACTERIZATION OF α‐ AND β‐AMYLASES FROM ZEA MAYS MALT AND STATISTICAL ANALYSIS APPROACH OF THE DEGRADATION OF MANIOC STARCH
Authors: CURVELO‐SANTANA JOSÉ CARLOS , FERREIRA GRAZIELA BATISTA , BIAZUS JOANA PAULA MENEZES , DE SOUZA ROBERTO RODRIGUES , TAMBOURGI ELIAS BASILE
Published: May 2008

This work examined the degradation of manioc starch by amylases from maize malt and the biochemistry characterization of enzymes. Enzyme characterization showed that the maize malt amylases have optimal pH between 4.5 and 6.5, with optimal temperature between 50 and 90C; Michaelis‐Menten constant (Km) and maximum velocity of starch hydrolysis (Vmax) values for starch hydrolysis by maize malt were 7.69 × 10−2 g/L and 7.69 × 102 g/L/min, respectively. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis analysis of the eluted sample from ion‐exchange expanded bed chromatography showed that molecular weights of α‐ and β‐amylases from maize malt were of 67.4 and 47.5 kDa, respectively. The hydrolysis times had been found between 20 and 30 h, and the higher hydrolysis yield values were about 31%; it was higher than 27% (cited by literature) and was obtained at 65C and at 9 and 11% (w/v) of any starch concentration studied.

PRACTICAL APPLICATIONS

The results of this work have practical uses in the hydrolysis process of starch by food industries (beers, beverages, bakeries, syrups and others). This work shows optimal conditions of using the amylases from maize malt in starch hydrolysis. Recently, a search for new energetic sources has been unleashed after the pronounced governing of various countries on a possible energetic crisis. At present, Brazil is in search of methods that will increase the ethanol offer by production of combustible alcohol. Thus, this study shows the optimal conditions to produce fermentable syrup from manioc starch and as a potential substitute to sugarcane in alcohol production.
Random Reduction in Fingerprint Bit Density Improves Compound Recall in Search Calculations Using Complex Reference Molecules
Authors: Wang Yuan , Geppert Hanna , Bajorath Jürgen
Published: May 2008

Fingerprints are bit string representations of molecular structure and properties and widely used tools to search databases for active molecules. It is well appreciated that molecular complexity and size effects lead to systematic errors in fingerprint similarity searching. For example, different studies have highlighted the caveats associated with preferential recognition of large compounds, irrespective of their activity, when complex molecules are used as templates for fingerprint calculations. In order to systematically study complexity relationships between reference and database molecules that are relevant for practical fingerprint similarity searching, we have designed sets of active molecules of increasing fingerprint bit density relative to average database compounds and potential hits and carried out systematic similarity search trials. We find that the more complex reference molecules are, the lower the search performance becomes. However, a major result has been that random deletion of bits that are set on in fingerprints of complex reference molecules generally improves compound recall, although these random bit density reductions also cause a loss in chemical information content. These results suggest a general search strategy for fingerprints that are sensitive to complexity effects when optimized active compounds are used as reference molecules.
Modulatory Effects of 6‐Carboxymethylthiopurine on Activated Murine Macrophages
Authors: De Paula Marcio L. , Braga Fernanda G. , Coimbra Elaine S. , Carmo Arturene M. L. , Teixeira Henrique C. , Da Silva Adilson D. , Souza Maria A. , Ferreira Ana Paula
Published: May 2008

The immunological activity of macrophages against pathogens in hosts includes the phagocytosis and the production of nitric oxide. We report herein the investigation of the effect of 6‐carboxymethylthiopurine on nitric oxide production by murine macrophages as well as its effect on the cell viability and proliferation after stimulus with Mycobacterium bovis bacille Calmette–Guérin, interferon‐gamma or a combination of both. J774A.1 macrophages stimulated or not by bacille Calmette–Guérin (20 μg/mL), interferon‐gamma or both, were cultured in the presence of 6‐carboxymethylthiopurine (125, 250 and 500 μm). Nitric oxide production was measured by the Griess method and cell viability/proliferation by the diphenyltetrazolium assay [3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide]. We observed an increase of J774A.1 cell proliferation after stimulus with bacille Calmette–Guérin at 125, 250 and 500 μm (69.1, 124.0 and 89.7%, respectively) and with interferon‐gamma at 125 and 250 μm (64.8% and 61.7%, respectively) (p < 0.05). In all cultures treated with 6‐carboxymethylthiopurine, interferon‐gamma‐activated nitric oxide production by J774A.1 cells decreased as well as when subjected to interferon‐gamma plus bacille Calmette–Guérin stimuli at 500 μm (p < 0.05). Altogether these data point to an anti‐inflammatory effect of 6‐carboxymethylthiopurine on stimulated macrophages.
Identification of 21 polymorphic microsatellites in the African parasitoid wasp, Psyttalia lounsburyi (Silvestri) (Hymenoptera: Braconidae)
Authors: BON M. C. , JONES W. , HURARD C. , LOISEAU A. , RIS N. , PICKETT C. , ESTOUP A. , FAUVERGUE X.
Published: May 2008

We have developed 21 dinucleotide repeat microsatellite loci from African populations of Psyttalia lounsburyi (Silvestri) (Hymenoptera: Braconidae), a parasitoid wasp of the olive fruit fly, as part of a study assessing the role of introgression/hybridization in the success of a biological control introduction. We proposed suitable conditions for polymerase chain reaction multiplexing. All 21 loci were polymorphic with two to 21 alleles per locus within the Kenyan and South African populations tested. Most of them were successfully amplified in two other Psyttalia species.
Development and characterization of 10 microsatellite markers for the semi‐evergreen tree species, Ligustrum ovalifolium (Oleaceae)
Authors: KODAMA KOSEI , YAMADA TAKAYUKI , MAKI MASAYUKI
Published: May 2008

Ligustrum ovalifolium is a semi‐evergreen tree distributed in the western part of Japan and southern Korea. This species contains an insular endemic variety, L. ovalifolium var. pacificum; this variety occurs only on the Izu Islands located south of the Japanese mainland Honshu. We isolated 10 polymorphic microsatellite loci from the species, and characterized them for 21 individuals from a population of L. ovalifolium. The primers developed in this study yielded an average 12.2 alleles per locus and an average expected heterozygosity of 0.78. These markers will be powerful tools for studying the genetic differentiation within the species.
Ten microsatellite loci from Solms‐laubachia eurycarpa (Brassicaceae)
Authors: YUE JIPEI , FELDHEIM KEVIN A , SUN HANG , REE RICHARD
Published: May 2008

Solms‐laubachia eurycarpa is a medicinal herb endemic to the Hengduan Mountains region of south‐central China. We screened a partial genomic library enriched for microsatellites and characterized 10 polymorphic loci for S. eurycarpa. The number of alleles per locus ranged from five to 15, with an average of 9.6. The observed and expected heterozygosities ranged from 0.2 to 0.725 and from 0.585 to 0.871, respectively. Amplification in closely related taxa was successful for most loci. The results indicate significant potential for the utility of these markers in studying the population genetics of S. eurycarpa and related species.
Isolation and characterization of microsatellite loci for Hymenaea courbaril and transferability to Hymenaea stigonocarpa, two tropical timber species
Authors: CIAMPI A. Y. , AZEVEDO V. C. R. , GAIOTTO F. A. , RAMOS A. C. S. , LOVATO M. B.
Published: May 2008

Hymenaea courbaril is a tropical timber species, intensely exploited and found in the Amazon, Atlantic Forest and Brazilian Cerrado biome. Nine highly polymorphic microsatellite loci were developed from a genomic library enriched for AG/TC repeats. In a total of 41 individuals, from two natural populations, seven to 13 alleles per locus were detected and expected heterozygosity ranged from 0.75 to 0.90. Seven loci were effectively transferred to Hymenaea stigonocarpa. High levels of polymorphism make the present primers useful for population genetic studies and are a powerful tool to investigate mating system, gene flow and spatial genetic structure.
A Judicial‐Mental Health Partnership to Heal Young Children in Juvenile Court
Authors: Lederman Judge Cindy S. , Osofsky Joy D.
Published: May 2008

In this article, we describe the background and issues to be addressed related to dependent children in juvenile court. In an important effort to systematically examine developmental functioning and treatment needs in maltreated and violence‐exposed young children, the Prevention and Evaluation of Early Neglect and Trauma (PREVENT) initiative of the Dependency Court Intervention Program for Family Violence, a national demonstration project in the Miami‐Dade Juvenile Court, developed a program to evaluate all infants, toddlers, and preschoolers who are adjudicated dependent by the court. The goal of the intervention is to raise awareness of the needs of infants and toddlers in juvenile court and to work toward healing the child. The PREVENT program involved the evolution of a judicial‐mental health partnership designed to assist the court in making more informed decisions about the best interest of the child by adding scientific knowledge about development, prevention, intervention, evaluation, and treatment. The outcome of the partnership and multidisciplinary approach is illustrated through presenting a case vignette of a mother and baby showing the challenges and strengths of intervention. Finally, we consider overall outcomes of the intervention and directions for the future.
Why Medical Child Support is Important—and Complex
Authors: Paikin Susan F. , White Judge A. Ellen
Published: May 2008

Courts resolving child support cases involving separated, divorced, and non‐marital children are charged with defining responsibility for health care coverage for the children under that order. This article explores historical and current medical child support requirements under Title IV‐D of the Social Security Act—the national child support enforcement (“IV‐D”) program. It analyzes legal requirements and policy recommendations, and provides a practical tool judges may use to determine whether health care coverage available to either or both parents is appropriate—that is, comprehensive, accessible, and affordable.
Targeting Underage Drinking and Driving in Juvenile and Domestic Relations Courts: The Reinforcing Alcohol Prevention (RAP) Program
Authors: Will Kelli England , Sabo Cynthia Shier
Published: May 2008

Alcohol use is a concern among our nation's least experienced drivers, and underage drinking contributes to the overall burden of traffic injury and mortality. The goal of the Reinforcing Alcohol Prevention (RAP) Program was to develop a court‐based program targeting underage drinking and driving among teens. An advisory board created the program which included changes to the drivers' licensing ceremonies and traffic dockets conducted in Juvenile and Domestic Relations Courts. Additions included 5‐minute videos of individuals in alcohol‐related crashes and a crash‐photo display. Exit evaluations garnering impressions/opinions of the program indicated 84% of teenagers felt every teen should view the presentation and 96% would be less likely to drive after drinking. The RAP Program has been well‐received by judges and participants and could be easily implemented by other jurisdictions.
Marine Polyphosphate: A Key Player in Geologic Phosphorus Sequestration
Authors: Diaz Julia , Ingall Ellery , Benitez-Nelson Claudia , Paterson David , de Jonge Martin D. , McNulty Ian , Brandes Jay A.
Published: May 2008

The in situ or authigenic formation of calcium phosphate minerals in marine sediments is a major sink for the vital nutrient phosphorus. However, because typical sediment chemistry is not kinetically conducive to the precipitation of these minerals, the mechanism behind their formation has remained a fundamental mystery. Here, we present evidence from high-sensitivity x-ray and electrodialysis techniques to describe a mechanism by which abundant diatom-derived polyphosphates play a critical role in the formation of calcium phosphate minerals in marine sediments. This mechanism can explain the puzzlingly dispersed distribution of calcium phosphate minerals observed in marine sediments worldwide.
Phosphorylation by p38 MAPK as an Alternative Pathway for GSK3β Inactivation
Authors: Thornton Tina M. , Pedraza-Alva Gustavo , Deng Bin , Wood C. David , Aronshtam Alexander , Clements James L. , Sabio Guadalupe , Davis Roger J. , Matthews Dwight E. , Doble Bradley , Rincon Mercedes
Published: May 2008

Glycogen synthase kinase 3β (GSK3β) is involved in metabolism, neurodegeneration, and cancer. Inhibition of GSK3β activity is the primary mechanism that regulates this widely expressed active kinase. Although the protein kinase Akt inhibits GSK3β by phosphorylation at the N terminus, preventing Akt-mediated phosphorylation does not affect the cell-survival pathway activated through the GSK3β substrate β-catenin. Here, we show that p38 mitogen-activated protein kinase (MAPK) also inactivates GSK3β by direct phosphorylation at its C terminus, and this inactivation can lead to an accumulation of β-catenin. p38 MAPK–mediated phosphorylation of GSK3β occurs primarily in the brain and thymocytes. Activation of β-catenin–mediated signaling through GSK3β inhibition provides a potential mechanism for p38 MAPK–mediated survival in specific tissues.
A General Model for Food Web Structure
Authors: Allesina Stefano , Alonso David , Pascual Mercedes
Published: May 2008

A central problem in ecology is determining the processes that shape the complex networks known as food webs formed by species and their feeding relationships. The topology of these networks is a major determinant of ecosystems' dynamics and is ultimately responsible for their responses to human impacts. Several simple models have been proposed for the intricate food webs observed in nature. We show that the three main models proposed so far fail to fully replicate the empirical data, and we develop a likelihood-based approach for the direct comparison of alternative models based on the full structure of the network. Results drive a new model that is able to generate all the empirical data sets and to do so with the highest likelihood.
Contact Value Formulae for the Density Profiles of the Electric Double Layer
Authors: Henderson Douglas J. , Bhuiyan Lutful B.
Published: May 2008

An exact sum rule, due to Henderson, Blum, and Lebowitz, for the contact value of the density profile of ions in a primitive model electrolyte next to a planar, nonpolarizable charged hard wall, has been known for some years. This result has a pleasing physical interpretation and is local. It has been useful in assessing the accuracy of theoretical approximations. However, a sum rule for the contact value of the charge profile for the same system has, until recently, not been known. A few years ago, Boda and Henderson proposed what they thought might be a useful, but approximate, local expression for the contact value of the charge profile at a weakly charged electrode. Very recent computer simulations indicate that this expression may well be exact at low electrode charge. Recently, Holovko, Badiali, and di Caprio have obtained a more general, but nonlocal, sum rule for the contact value of the charge profile that is valid for all electrode charge. In this paper, we develop an alternative, nonlocal, but nonrigorous expression for this quantity. Both the expression of Holovko et al. and our new expression are examined by means of computer simulations. The Holovko et al. expression is exact and, within numerical uncertainties, seems supported by our simulations. Although admittedly nonrigorous, our simpler expression is in seemingly reasonable agreement with simulation and thus appears to be useful. The relation between the two expressions has not been established.
Evaluating the interaction between genotype and water stress in the hybrid poplar – Septoria musiva pathosystemThis note is one of a selection of papers published in the Special Issue on Poplar Research in Canada.
Authors: LeBoldus Jared M. , Blenis Peter V. , Thomas Barb R.
Published: May 2008

Septoria musiva , the causal agent of Septoria canker, has caused widespread damage to plantations of hybrid poplar across North America. A greenhouse experiment was conducted to evaluate the size of interactions between the genotype factors of (i) clone, (ii) isolate, and (iii) the clone–isolate interaction and the environmental factor of water stress. Four clones of hybrid poplar were inoculated with four isolates of S. musiva and subsequently exposed to two levels of water stress (stressed and unstressed). Tree height, root collar diameter (RCD), and disease severity were measured 56 d after inoculation. Water stress reduced height and RCD growth by approximately 30% but did not affect disease severity (P = 0.258). Of the explained variability, 97.5% was attributable to genotype effects (89% from clone, 0% from isolate, and 8.5% from clone–isolate interaction). The remaining 2.5% of the variation was accounted for by the genotype – water stress interaction. These results suggest that clonal effects will be more important determinants of disease severity under greenhouse conditions than genotype – water stress interactions.
Sap velocity as an indicator of diurnal and long-term hydraulic resistance changes in mature ‘Walker’ hybrid poplar treesThis article is one of a selection of papers published in the Special Issue on Poplar Research in Canada.
Authors: Kort J. , Blake T.J.
Published: May 2008

Hydraulic resistance directly limits sap flow in trees so that understanding water-use patterns in poplar trees requires knowledge about diurnal and long-term changes in resistances in the soil–plant–atmosphere continuum. Granier thermal dissipation probes were used for continuous measurements of sap velocity (V) changes over time and whole-tree water-use patterns in the main stems of ‘Walker’ hybrid poplar trees. When atmospheric demand was low, V depended only on solar radiation (Rg) and vapour pressure difference (VPD). However, on warm, sunny days, midday V decreased, despite a constant leaf water potential (Ψl) of –1.5 MPa. Because bulk soil water potential (Ψs) did not change significantly, the constant Ψl implied that the water potential difference (ΔΨ) remained diurnally constant. Although stomatal control would explain changes in V when VPD was low, an increase in hydraulic resistance was required to explain the decrease in V when VPD was high. Xylem cavitation was ruled out as a cause because the apparent increase in resistance reversed in late afternoon, while VPD was still high. Mid-August irrigation immediately increased daily V, which was attributed to a change in ΔΨ because of less negative Ψs. A gradual increase in sap flow over two weeks following irrigation implied a decrease in plant hydraulic resistance, most likely attributable to new root growth. It was concluded that hydraulic resistance changes, both diurnal and in the longer term, occurred primarily at the rhizosphere or root level.
Floods, fire, and ice: disturbance ecology of riparian cottonwoodsThe review is one of a selection of papers published in the Special Issue on Poplar Research in Canada.
Authors: Rood Stewart B. , Goater Lori A. , Mahoney John M. , Pearce Cheryl M. , Smith Derald G.
Published: May 2008

Cottonwoods are poplar trees that are well adapted to dynamic riparian, or streamside, zones throughout the Northern Hemisphere. Here we assess the influences of three prominent physical disturbances, floods, fire, and ice, on cottonwood population ecology. We emphasize cottonwoods along rivers from the “Crown of the Continent”, the central Rocky Mountain zone around the Canada – United States border, where five Populus species overlap and four hybridize. Moderate to major floods scour banks and deposit bars, creating barren and moist colonization sites that are essential for cottonwood seedling recruitment. Floods also scarify shallow roots, thus promoting clonal suckering, especially for the section Tacamahaca species: narrowleaf cottonwood ( Populus angustifolia James), balsam poplar ( Populus balsamifera L.), and black cottonwood ( Populus trichocarpa Torr. & A. Gray). Fire would naturally be less frequent in some riparian zones because of the moist conditions and firebreaks provided by the streams, but with human use, floodplain forest fires have probably increased. Following fire, regrowth through clonal root and shoot suckers can be prolific for the Tacamahaca species, but is limited for the section Aigeiros , prairie cottonwood ( Populus deltoides Bartr.). River ice, and especially ice drives that accompany winter or spring break-up, provide powerful riparian disturbances that have often been neglected. Ice drives generate barren sites for seedling colonization, shear shoots, and scarify roots promoting shoot and root suckering, and sever branches, enabling dispersive clonal branch propagation. Following studies along many regional rivers, we conclude that: (i) riparian cottonwoods are tolerant of, and dependent upon, occasional physical disturbance for population rejuvenation; (ii) differing disturbance responses contribute to niche differentiation across the Populus species; (iii) different disturbances enable varied spatial and temporal patterns of cottonwood establishment, including fringe, general, and patch recruitment; and (iv) natural disturbance regimes probably favor native cottonwoods and disfavor some invasive, woody plants. River damming and flow regulation often attempt to attenuate flood and ice disturbance, a management objective that may hinder the perpetuation of native floodplain forests. We recommend that river resource managers seek to allow flood and ice disturbance, and additionally, fire may provide a managed disturbance that could rejuvenate overmature cottonwood groves along some regulated rivers.
Patterns of tree stem decline along a snow-drift gradient at treeline: a case study using stem analysis
Authors: Payette Serge , Delwalde Ann , Morneau Claude , Lavole Claude
Published: May 2008

Current hypotheses on conifer tree stem degradation at treeline indicate the influence of frost desiccation caused by dehydration of wind-exposed needles above the snowpack because of frozen soil or wind abrasion. Here, we examine, in an exploratory study, the potential of detailed stem analysis to identify other causal factors at a subarctic treeline site using black spruce (Picea mariana (Mill.) BSP.) trees distributed along a wind-exposure gradient and showing various degrees of stem damage, from the normal, conical growth form to the mat growth form. Temporal patterns of stem development revealed a relatively integrated growth system within the tree as long as the normal arborescent form was maintained. With the gradual loss of the normal form owing to defoliation, the growth system of the damaged trees became fragmented into a wind-exposed (west–ast), horizontal component and a vertical (below–bove snowpack) component outlined by the asymmetric development of stem and foliage. Although cool growing seasons reduce tree-ring growth, frost events in July appear also influential, possibly when killing frosts occur during bud break. The impact of such abrupt events may have a long-enduring influence on radial growth, a factor much neglected in dendroclimatological studies of boreal and subarctic environments. Stem degradation may be initiated by the changing position of the snowpack line associated with variable snow precipitation during several consecutive years, thus inducing a shifting erosional zone along the stem most effective when temperatures are below average, i.e., likely the result of mechanical defoliation caused by the synergistic influence of snow and ice abrasion during blizzards and severe windchill conditions on the brittle, cold-exposed needles. Our results suggest that sustained winter defoliation at treeline has an overwhelming influence on subsequent radial growth. More dendroecological studies and experimental field work are needed to test our conclusions. Keywords: stem analysis, treeline, black spruce, winter defoliation, tree rings, subarctic.
La plasticité phénotypique des caractères anatomiques foliaires chez le Festuca rubra L. (Pcaceae)
Authors: Dubé Martin , Morisset Pierre
Published: May 2008

The phenotypic plasticity of nine anatomical leaf characters of Festuca rubra was studied through a transplantation experiment. Twelve genotypes from four habitats (salt marshes, coastal rocks, coastal sands, and ruderal places) were submitted to five treatments in a garden. An analysis of variance shows that almost all these characters were modified by treatments. Nevertheless, in most cases, the greatest part of the variation observed was genetic rather than plastic. Morever, it appears that genotypes responded quite differently to the treatments. The use of these characters in the taxonomy of F. rubra is discussed. Keywords: Festuca rubra, leaf anatomy, phenotypic plasticity.
The effect of cadmium, zinc, and copper on the growth, tolerance index, metal uptake, and production of malic acid in two strains of the grass Festuca rubra
Authors: Harrington Christopher F. , Roberts David J. , Nickless Graham
Published: May 2008

The effect of zinc, cadmium, and copper on the growth, tolerance indices, and metal uptake of Merlin Festuca rubra from Trelogan mine, Wales, and Cascade Festuca rubra, a normal grass, were investigated by growth experiments in metal amended nutrient solution. The effect of zinc or copper on the malic acid concentration in both strains was also investigated. Fresh weight was shown to be a good indicator of growth for experiments over a 28-day period. Using a parallel method to calculate tolerance indices, the Merlin strain was significantly more tolerant to 50.0 mg L−1 Zn (P = 0.005), 1.0 mg L−1 Cd (P = 0.004), and 1.0 mg L−1 Cu (P = 0.012), compared with Cascade. The upper critical tissue concentrations showed that Merlin could withstand twice as much zinc and 12 times the amount of cadmium in its shoot tissue before the onset of toxicity, compared with Cascade. However, the levels for copper were similar for both strains. The carboxylic acids present in both Cascade and Merlin were qualitatively identified using high performance liquid chromatography. The concentration of malic acid present in the shoot tissue of each strain was determined and showed that Merlin contained a greater amount of malic acid compared with Cascade and that the levels increased on exposure to zinc, but not with copper. Keywords: metal tolerance, Festuca rubra, malic acid, high performance liquid chromatography (HPLC), upper critical concentrations.
Further polyamine analyses of leguminous seeds and seedlings: the occurrence of novel linear, tertiary branched and quaternary branched pentaamines
Authors: Hamana Koel , Niitsu Masaru , Samejima Keijiro
Published: May 2008

Polyamines of the seeds, seedlings, and some other tissues of 15 leguminous plants were analyzed by high performance liquid chromatography and gas chromatography. A novel tertiary branched pentaamine, N5-aminobutylhomospermine, was detected in the seed of Vicia villosa and another novel quaternary branched pentaamine, N4-bis(aminopropyl)spermidine, in the seed of Crotalaria spectabilis. Norspermine and a novel linear pentaamine, caldopentamine, were found in the seed of Gleditschia japonica. Other unusual polyamines such as norspermidine, homospermidine, thermospermine, N4-methylthermospermine, homospermine, and N-(3-aminopropyl)aminopropanol occur widely within leguminous seeds. Nine groups of plant response were found with respect to increases of diaminopropane, putrescine, cadaverine, and agmatine in the leguminous seedlings after germination. Keywords: leguminae, seed, seedling, polyamine.
Environmental factors affecting expression of resistance to pink snow mold caused by Microdochium nivale in winter wheat
Authors: Nakajima T. , Abe J.
Published: May 2008

The effects of prehardening growth, cold-hardening temperatures, duration of cold hardening, light intensity, and light period during cold hardening on the development of resistance to Microdochium nivale in winter wheat were studied under controlled environment conditions. Resistance was expressed as the median lethal incubation days (LI50) measured by the optimum temperature inoculation method of T. Nakajima and J. Abe. Plant growth at 20:15 °C (light:dark) had the largest effect on augmenting resistance to M. nivale in winter wheat, but conditioning at low temperatures was essential for expression of resistance. Low temperature conditioning at 6–4 °C under low light intensities initiated a rapid development of M. nivale resistance; this process was slower at 4–12 °C. ‘PI 173438’, resistant to snow molds but not to low temperatures, required lower temperatures during cold hardening for full expression of resistance to M. nivale than ‘Nanbukomugi’, which was moderately resistant to snow molds and low temperatures. When conditioned at 2 °C, the plants subjected to the dark remained susceptible but developed resistance rapidly when exposed to low light intensities of 150 μmol ∙ m−2 ∙ s−1. Extending the light period from 8 to 16 h did not affect the expression of resistance to M. nivale. These results suggest that the pattern of development of snow mold resistance is substantively different from that involved in freezing tolerance, although both appear to be conditioned by low temperatures. Keywords: Monographella nivalis, Fusarium nivale, Triticum aestivum L., cold hardiness, snow mold, winter wheat.
The role of mucilage in the attachment of conidia, germ tubes, and appressoria in the saprobic aquatic Hyphomycetes Lemonniera aquatica and Mycocentrospora filiformis
Authors: Au D. W. T. , Jones E. B. G. , Moss S. T. , Hodgkiss I. J.
Published: May 2008

Spore attachment of the saprobic aquatic Hyphomycetes Lemonniera aquatica and Mycocentrospora filiformis was compared on Thermanox cover slips at the scanning and transmission electron microscope levels. The strength of attachment to Perspex discs was measured with the Fowler cell adhesion measurement module. Data are presented on the initial attachment of conidia and subsequent attachment of germ tubes, hyphae, and appressoria. Attachment at all stages was mediated by mucilage. Both fungi exhibited a similar strength of initial conidial attachment, but attachment resulted from different strategies: (i) in L. aquatica, by active release of mucilage as a result of a thigmotropic response to the substratum; (ii) in M. filiformis, by a passive process involving attachment by pre-existing conidial mucilage prior to contact with the substratum. The strength of attachment increased with settlement time. A fast germination rate, concurrent with mucilage production, resulted in the firm attachment of L. aquatica conidia, while initial germination in M. filiformis was slow and this corresponded to a comparatively weaker conidial attachment. Further increase in the strength of attachment was the result of greater hyphal development, and most importantly, by appressorium formation. All these structures were enrobed in a mucilaginous sheath, although variations were observed in the morphology and texture of mucilages. This suggested differences in chemical composition of mucilage (i) between the two fungi, and (ii) among different structures of the same fungus. Keywords: aquatic Hyphomycetes, appressorium, attachment, germination, mucilage, ultrastructure.
Water and soil chemistry, floristics, and phytosociology of the extreme rich High Creek fen, in South Park, Colorado, U.S.A.
Authors: Cooper David J.
Published: May 2008

An extreme rich fen complex located in South Park, Colorado, is the most southern representative of this ecosystem type known in North America and the first described from the Southern Rocky Mountains. The fen is fed by ground water emerging from glacial outwash and has pH ranging from 7.6 to 8.3 and Ca2+ concentrations greater than 50 mg kg−1. The very low precipitation–evapotranspiration ratio in South Park causes Na+ and Mg2+ salts to accumulate in some soils, forming sodic peats that support halophyte communities. Character species of this fen include Kobresia simpliciuscula, Trichophorum pumilum, Carex scirpoidea, Carex microglochin, Carex livida, Utricularia ochroleuca, Triglochin palustris, Triglochin maritima, Salix Candida, Salix myrtillifolia, Salix serissima, Thalictrum alpinum, and Scorpidium scorpioides. A hierarchical classification of the vegetation is developed using numerical and table methods and includes 14 aquatic, peatland expanse, and salt flat communities. The most floristically similar fens occur in northern Ontario, northwestern Wyoming, and northern Montana. Keywords: peatland, extreme rich fen, South Park, Colorado, Rocky Mountains.
Pterosporidium gen.nov. to accommodate two species of Anthostomella from mangrove leaves
Authors: Ho W. H. , Hyde Kevin D.
Published: May 2008

Anthostomella rhizomorphae and Anthostomella rhizophorae, associated with foliar diseases of mangrove trees, are re-examined. In both species, the asci are thin-walled and clavate and contain unicellular brown ascospores. The ascospores lack a germ slit and are covered in a thin paperlike sheath. These species clearly do not belong in Anthostomella, and a new genus, Pterosporidium, is described to accommodate them. Pterosporidium is probably best accommodated in the Phyllachoraceae. Keywords: Anthostomella, fungi, Pterosporidium, mangrove, pathogen, Phyllachoraceae.
Genetics of Cronartium ribicola. III. Mating System
Authors: Gitzendanner Matthew A. , Dupper Gayle E. , White Eleanor E. , Foord Brett M. , Hodgskiss Paul D. , Kinloch Jr. Bohun B.
Published: May 2008

Lack of genetic markers has hindered the study of the mating system of Cronartium ribicola, an exotic forest pathogen Meeting natural and cultivated white pines throughout North America. Isozymes, randomly amplified polymorphic DNA (RAPDs), and restriction length polymorphisms (RFLPs) were used to study the mating system of this rust. Heterozygosity (outcrossing) in diploid telia was demonstrated by analysis of cultures derived from the meiotic products (basidiospores) of individual telia. Families of basidiospores cultured from single telia were used to test for Mendelian segregation and for conformance of loci to Hardy–Weinberg equilibrium. A total of 18 polymorphic loci were identified with the three marker systems. All except for three RAPD loci showed Mendelian segregation in the single-telium families. To quantify the level of outcrossing, gene and genotype frequencies were calculated for families from a single population. Up to 24 families were surveyed with isozymes, 14 with RAPDs, and 18 with RFLPs. Except for one isozyme locus (MPI) in one sample, all 14 loci tested with these families were in Hardy–Weinberg equilibrium, indicating random mating. Further studies, with a different sample from the same population, showed all three isozyme loci to be in Hardy–Weinberg equilibrium. The three marker systems were consistent as to the amount of variation detected. Resistance selection and breeding programs must consider the implications of genetic recombination that outcrossing affords the rust. Keywords: isozymes, RAPDs, RFLPs, Hardy–Weinberg equilibrium, white pine blister rust.