bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sexual dimorphism of reproductive allocation at shoot and tree levels in Zanthoxylum ailanthoides, a pioneer dioecious tree
Authors: Matsuyama Shuhei , Sakimoto Michinori 
Published: October 2010

Sexual dimorphisms are often found in reproductive allocation and vegetative growth, and these sexual dimorphisms may lead to a reduction of subsequent reproductive allocation in woody dioecious species. However, in some species, female-biased reproductive allocation does not result in a reduction of subsequent reproductive allocation in females. To clarify the mechanisms underlying this phenomenon, we studied the dioecious tree Zanthoxylum ailanthoides Sieb. et Zucc., in which leafing and inflorescence development occur sequentially. Reproductive allocation and vegetative growth were examined in both sexes at the shoot and tree levels. At tree level, they were evaluated with respect to flowering frequency and annual tree-ring width over 5 years. Reproductive allocation per shoot in females was 1.7× that in males. The ratio of reproductive to total current-year shoots per tree in males was 1.2× that in females. Reproductive allocation in females exceeded that of males by a factor of 1.5 at the tree level, which was less than that at the shoot level, owing to modular integrity. Biased vegetative growth was not detected at the leaf, shoot, or tree level, suggesting that a compensatory mechanism is not employed by this species. The results support the conclusion that a species-specific phenophase sequence of Z. ailanthoides enables females to achieve consecutive reproductive allocation.
Localized increases of polyphenol concentration and antioxidant capacity in relation to the differential accumulations of copper and cadmium in roots and in shoots of sunflower
Authors: Yaakoubi Hnia , Samson Guy , Ksontini Mustapha , Chaibi Wided 
Published: October 2010

In this study, we examined the relevance of polyphenols in the response of sunflower plants to acute Cu and Cd stresses. More specifically, we aimed to correlate spatially and temporally the accumulation of polyphenols with the occurrence of oxidative stress, and to estimate their contribution to the antioxidant capacities. Under our experimental conditions, the presence of Cu and Cd (75 µmol·L–1) in the nutrient solution caused oxidative damage, as detected by the accumulation of malondialdehyde, in roots of Cu-treated plants and in leaves of Cd-treated plants; in the latter, significant inhibition of photosynthesis also occurred. These effects were in agreement with the preferential accumulation of Cu in the roots and the greater translocation of Cd to the shoots. This oxidative damage was associated with a concerted plant response, characterized by stimulation of phenylalanine ammonia-lyase, ascorbate peroxidase, and guaiacol peroxidase activities, and by the accumulation of polyphenols whose concentrations were closely correlated (R2 = 0.95) to the total antioxidant capacity of plants extracts. Globally, the co-occurrence of oxidative damages and polyphenol accumulation, and the correlations among polyphenol concentrations, total antioxidant capacities, and stimulations of the peroxidases support the involvement of polyphenols in protection against oxidative damage generated by Cu and Cd in plants.
Experimental seismic behavior of a five-storey double-midply wood shear wall in a full scale building
Authors: Pei Shiling , van de Lindt John W. , Ni Chun , Pryor Steven E. 
Published: October 2010

In July 2009, a full-scale six-storey platform wood frame apartment building was subjected to a series of earthquakes at the world’s largest shake table in Miki, Japan. Two double-midply shear wall stacks were installed in the building from the first storey through to the fifth storey. A continuous anchor tie-down system (ATS) was used to prevent overturning and allow the shear walls to develop their full lateral load capacities. This paper focuses on the behavior of the stacked double-midply shear wall in a full-scale midrise building during a series of triaxial shakes scaled for the city of Los Angeles, California. The stacked midply shear wall achieved a maximum interstorey deformation of 40.4 mm (equivalent to 1.64% drift). The uplift forces measured at the bottom storey of the stacked wall exceeded 760 kN, indicating the need for substantial tie-down systems for this type of wall when utilized in a midrise platform wood frame building.
Influence of aggregate size on the mechanical and transport properties of concretes and concrete-equivalent mortars
Authors: Özbay Erdoğan 
Published: October 2010

In this study, the influence of the aggregate size on the mechanical and transport properties of concrete and concrete-equivalent mortars is investigated. A concrete mixture was proportioned having a water–cement ratio of 0.45 and a cement content of 450 kg/m3 with a maximum aggregate size of 22.4 mm. Then, keeping the total aggregate surface area constant, three mixtures were proportioned with the same water–cement ratio, but the maximum aggregate size decreased to 16, 8, and 4 mm using the concrete-equivalent mortar method. Mechanical properties including compressive strength, splitting tensile strength and transport properties including rapid chloride permeability, water sorptivity, water absorption, and water permeability tests were performed at 7 and 28 d. Test results revealed that decreasing the maximum aggregate size increased the water permeability, rapid chloride permeability, water absorption, and sorptivity values, but decreased the compressive and split tensile strengths of concrete and concrete-equivalent mortars.
Strengthening of a concrete masonry wall subject to lateral load with sprayed glass-fibre-reinforced polymer
Authors: Haddad M. A. , Shaheen E. , Parsekian G. A. , Tilleman D. , Shrive N. G. 
Published: October 2010

Unreinforced hollow concrete masonry walls could be used to construct basements if strengthened to resist the lateral load. Two face-shell-bedded concrete masonry walls were constructed, 3 m high by 6 m long. As a simple strengthening technique, one wall was sprayed with glass-fibre-reinforced polymer (GFRP) on one side to a nominal average thickness of 5 mm. The walls were subjected to distributed point loading simulating increasing pressure from top to bottom of the wall. Support conditions were applied to simulate the walls being part of a basement. The plain wall failed with a failure line cracking pattern at a lateral load of 44 kN. The sprayed wall failed in a much more brittle fashion when the load reached 330 kN. The GFRP suffered a mode III tear at the bottom course. The results indicate that spraying a plain masonry wall with GFRP increases its ability to resist lateral load considerably, and that the process could be improved in terms of both the thickness of the layer and the area of wall covered to achieve a specific target. The two walls were analyzed using the yield-line, fracture-line, and failure-line methods. The failure-line method was improved by accounting for the stiffness orthotropy of masonry and gave the most accurate prediction of these plastic design methods. A finite element model of the masonry provided the most accurate prediction of capacity.
Target excitation dependence of degree of multifractality and critical exponent in ultrarelativistic nuclear collision
Authors: Ghosh Dipak , Deb Argha , Saha Ruma , Das Rupa 
Published: October 2010

The target excitation dependence of the degree of multifractality and critical exponent of pions produced for the 16O-AgBr interaction at 60 AGeV has been investigated. To study target excitation dependence, the data for the produced pions were distributed into three sets, depending on the number of grey tracks (ng). The different sets correspond to the different degrees of target excitation. The probability G-moments were used for the analysis in pseudorapidity space. The analysis reveals that the produced particle density distribution possesses multifractal structure for all degrees of target excitation (0 ≤ ng ≤ 3, 4 ≤ ng ≤ 7, and ng ≥ 8). The distribution Levy index and the phase transition critical exponent are calculated. The study indicates the non-thermal phase transition, but it does not show evidence for the second-order phase transition.
Unsteady flow of a generalized Oldroyd-B fluid due to an infinite plate subject to a time-dependent shear stress
Authors: Vieru D. , Fetecau Corina , Fetecau C. 
Published: October 2010

The unsteady flow of an incompressible generalized Oldroyd-B fluid induced by an infinite plate subject to a time-dependent shear-stress is studied by means of the Fourier cosine and Laplace transforms. The solutions that have been obtained, written under integral and series form in terms of the generalized Ga,b,c(·,t) functions, are presented as a sum of the Newtonian solutions and the corresponding non-Newtonian contributions. They satisfy all imposed initial and boundary conditions, and for λ and λr → 0 reduce to the Newtonian solutions. Furthermore, the similar solutions for generalized Maxwell fluids as well as those for ordinary fluids are also obtained as limiting cases of general solutions. Finally, to reveal some relevant physical aspects of the obtained results, the diagrams of the velocity field v(y, t) have been depicted against y for different values of t and of the material and fractional parameters.
Frequency of virulence genes and antibiotic resistances inEnterococcusspp. isolates from wastewater and feces of domesticated mammals and birds, and wildlife
Authors: Lanthier Martin , Scott Andrew , Lapen David R. , Zhang Yun , Topp Edward 
Published: October 2010

Enterococci are gastrointestinal tract residents and also an important cause of nosocomial infections. To understand which species, virulence determinants, and antibiotic resistances are prevalent in enterococci shed by various hosts groups, a total of 1460 strains isolated from 144 fecal samples obtained from wastewater, domesticated mammals and birds, and wildlife were characterized. Identification of isolates to the species level showed that Enterococcus faecalis was dominant in domesticated mammals and birds and wildlife feces, whereas Enterococcus faecium was dominant among wastewater isolates, and that no single Enterococcus species could be associated with a specific host group. The frequency of 12 virulence determinants was evaluated among isolates, but no single virulence determinant could be associated with a specific host group. Resistance to 12 antibiotics was evaluated among isolates, and it was shown that the highest frequency of resistance at breakpoint concentration was found in domesticated mammals and birds (P ≤ 0.05 for 4 antibiotics). Our results suggests that (1) species identification and virulence typing of Enterococcus spp. isolates are not useful for the identification of the host groups responsible for fecal contamination of water by microbial source tracking and that (2) antibiotic use for clinical, veterinary, or animal husbandry practices is promoting resistance.
Occurrence and dominance of yeast species in naturally fermented milk from the Tibetan Plateau of China
Authors: Bai Mei , Qing Manjun , Guo Zhuang , Zhang Yong , Chen Xia , Bao Qiuhua , Zhang Heping , Sun Tian-song 
Published: October 2010

To determine which yeasts are present in the naturally fermented milks of China, 69 samples made by the nomads of Tibet were collected from the Tibetan Plateau in China. From these samples, 225 strains of yeast were isolated and identified using conventional microbiological analysis and gene sequencing analysis of the D1/D2 domain of the large subunit (26S) ribosomal DNA. The results showed that the total concentration of yeasts in these samples ranged from 5.01 to 8.97 log10 colony-forming units (CFU)/mL (6.91 ± 1.02 log10 CFU/mL; mean ± SD). The number of cultivable yeasts was higher in the samples from Qinghai (7.55 ± 0.75 log10 CFU/mL) than those from Tibet (6.21 ± 0.79 log10 CFU/mL, P < 0.05). Moreover, there were 15 phylotypes in these 69 samples. Among these phylotypes, Kluyveromyces marxianus (49.3%, frequency percentage), Saccharomyces cerevisiae (62.3%), and Pichia fermentans (46.4%) appeared frequently and can be considered the most common culturable species in naturally fermented milk products. Traditional fermented Mongolian cow milk featured a wide diversity of yeast species, including Issatchenkia orientalis , Kazachstania unisporus , Rhodotorula mucilaginosa , Candida pararugosa , Torulaspora delbrueckii , Geotrichum sp., Kazachstania unisporus , Geotrichum fragrans , Debaryomyces hansenii , Yarrowia lipolytica , Trichosporon gracile , and Pichia membranifaciens . This study provides new data on yeast composition in naturally fermented milk and shows the yeast biodiversity of fermented milk products from the Tibetan Plateau of China.
Responses of Staphylococcus aureus exposed to HCl and organic acid stress
Authors: Rode Tone Mari , Møretrø Trond , Langsrud Solveig , Langsrud Øyvind , Vogt Gjermund , Holck Askild 
Published: October 2010

Staphylococcus aureus is an important food poisoning bacterium. In food preservation, acidification is a well-known method. Permeant weak organic acids, like lactic and acetic acids, are known to be more effective against bacteria than inorganic strong acids (e.g., HCl). Growth experiments and metabolic and transcriptional analyses were used to determine the responses of a food pathogenic S. aureus strain exposed to lactic acid, acetic acid, and HCl at pH 4.5. Lactic and acetic acid stress induced a slower transcriptional response and large variations in growth patterns compared with the responses induced by HCl. In cultures acidified with lactic acid, the pH of the medium gradually increased to 7.5 during growth, while no such increase was observed for bacteria exposed to acetic acid or HCl. Staphylococcus aureus increased the pH in the medium mainly through accumulation of ammonium and the removal of acid groups, resulting in increased production of diacetyl (2,3-butanedione) and pyrazines. The results showed flexible and versatile responses of S. aureus to different types of acid stress. As measured by growth inhibition, permeant organic acid stress introduced severe stress compared with the stress caused by HCl. Cells exposed to lactic acid showed specific mechanisms of action in addition to sharing many of the mechanisms induced by HCl stress.
Natural and logging disturbances in the temperate rain forests of the Central Coast, British Columbia
Authors: Pearson Audrey F. 
Published: October 2010

Natural disturbances frame the spatial and temporal processes of ecosystems and are the foundation for ecosystem-based management. In the coastal temperate rain forests of British Columbia, landscape patterns of natural disturbances and their contrasts with logging are not well documented. Stand-replacing disturbances over the past 140 years were investigated for the Central Coast (1.5 million ha) at regional and local scales using a combination of aerial photograph interpretation and forest management GIS databases. At the regional scale, stand-replacing natural disturbances affected 3.1% of the forested area. The extent of natural disturbances was not strongly affected by the scale of analysis. In contrast, spatial pattern and scale were essential for discerning the full impact of logging. At the regional scale, logging affected 5.4% of the forested area. Within watersheds, however, logging occurred primarily in valley bottoms (81% ± 4%) with 59% ± 10% of valley bottom areas logged, 10 times the area of natural disturbances. Watershed size strongly affected riparian zones, with active floodplains comprising 53% ± 5% of valley bottom area in large (>20 000 ha) watersheds. In physiographically diverse landscapes, geomorphic features (such as watersheds, valley bottoms, and fluvial landforms) are crucial for determining disturbance processes and effects of logging at ecologically relevant scales.
Linear mixed-effects models for estimating biomass and fuel loads in shrublands
Authors: Pearce H.G. , Anderson W.R. , Fogarty L.G. , Todoroki C.L. , Anderson S.A.J. 
Published: October 2010

Shrubland biomass is important for fire management programmes and for carbon estimates. Aboveground biomass and the combustible portion of biomass, the fuel load, in the past have been measured using destructive techniques. These techniques are detailed, highly labour intensive, and costly; hence, an alternative approach was sought. The new approach used linear mixed-effects models to estimate biomass and fuel loads from easily measured field variables: shrub overstorey height and cover, and understorey height and cover. Site was regarded as a random effect. Sampling sites were located throughout New Zealand and included a range of shrubland vegetation types: manuka ( Leptospermum scoparium J.R. Forst. et G. Forst.) and kanuka ( Kunzea ericoides (A. Rich.) J. Thomps.) scrub and heath, pakihi (mixed low heath, fern, and rushes), and gorse ( Ulex europaeus L.). The approach was extended and confidence intervals were constructed for the regression models. Statistical analysis showed that understorey height and overstorey cover were significant (at the 5% level) in some cases. Overstorey height was highly significant in all cases (p < 0.0001), allowing development of models useful to the operational user. The models allow rapid estimation of average fuel loads or biomass on new sites, and double sampling theory can be applied to calculate the error in the resultant biomass estimate.
Long fire cycle in northern boreal Pinus forests in Finnish Lapland
Authors: Wallenius T. H. , Kauhanen H. , Herva H. , Pennanen J. 
Published: October 2010

Knowledge of past forest fire regimes is important for developing management plans for conservation areas and for predicting the probable effects of forest management and climate change on the structure and dynamics of forests. In this study, fire scars on living and dead trees were systematically sampled on 256 study plots in three landscapes in northeastern Finland dominated by Scots pine ( Pinus sylvestris L.). A total of 1030 disks or partial cross sections from different trees, including scars from 98 distinct forest fires, were dendrochronologically dated with an accuracy of 1 year or better. The extraordinarily well-preserved old Pinus snags and stumps allowed us to reconstruct annual tree-ring and fire chronologies beginning from the year AD 653. The fire cycles in the studied landscapes were exceptionally long for a boreal region dominated by Pinus, on average 350 years during the last millennium. This demonstrates that the fire regimes of poorly studied remote regions cannot be extrapolated from fire regimes of sites examined in more detail. Based on statistics on lightning-ignition densities, we suggest that most of the fires detected in this study were ignited by humans. The reconstructed past fire cycles were probably shortened by human influence.
Allometric models for predicting the aboveground biomass of Canada yew (Taxus canadensis Marsh.) from visual and digital cover estimates
Authors: Quint Thomas C. , Dech Jeffery P. 
Published: October 2010

The objectives of this study were to evaluate visual and digital estimates of percent cover as source data and to develop cover-based allometric models for the prediction of aboveground biomass of Canada yew ( Taxus canadensis Marsh.). Cover was determined from visual assessment and digital images captured over 25 plots (1 m2) at a model training site near Timmins, Ontario. Linear and power functions were fit to the cover–biomass data to develop models of foliage, stem, and total aboveground biomass. Both sources of cover data produced models that explained between 70% and 85% of the variance in the training data, with root mean square error estimates ranging from 27 g·m–2 (foliage) to 85 g·m–2 (total). Models based on visual cover data performed consistently better and were tested on independent data. Stem and total biomass were underestimated in the model testing data set; however, prediction statistics indicated that the linear and power forms of foliage biomass models were validated by the testing data. Final models of foliage biomass were developed from the entire data set, with mean absolute errors of 18.3 and 18.7 g·m–2 for the linear and power forms, respectively. Additional variables (e.g., plant height, age) may be required to provide general predictions of the woody biomass of Canada yew.
Habitat selection at multiple spatial scales in Northern Map Turtles (Graptemys geographica)
Authors: Carrière M.-A. , Blouin-Demers G. 
Published: October 2010

Understanding habitat use of declining species is essential for their management and successful recovery. We examined habitat selection at multiple spatial scales by Northern Map Turtles ( Graptemys geographica (Le Sueur, 1817)), a species at risk, in the St. Lawrence Islands National Park, Ontario, Canada. At the scale of the home range, Map Turtles generally avoided deep water (>2 m) and selected home ranges in waters <1 m deep. Importantly, turtles used home ranges with significantly more natural than developed shoreline. At the scale of the location, adult females used deep water more often and males preferred areas with surface cover. Management efforts should implement regulations concerning further shoreline development.
Morphometrics of the eyes and orbits of the nocturnal Swallow-tailed Gull (Creagrus furcatus)
Authors: Iwaniuk Andrew N. , Heesy Christopher P. , Hall Margaret I. 
Published: October 2010

The Swallow-tailed Gull ( Creagrus furcatus (Neboux, 1846)) is known for its nocturnal feeding habits and apparently large eyes. Despite frequent observations of its large eyes, detailed measurements of its eyes and orbits are wanting. Here, we provide a detailed analysis of the size and shape of the eye and orbits of this unique species in relation to a range of other gull species. Although the C. furcatus does have a slightly enlarged cornea and optical axis, neither the transverse orbit diameter nor the shape of its eye differs significantly from other larids. In addition, we found no significant difference between C. furcatus and other gulls in terms of its orbit dimensions and orbit orientation. We therefore conclude that C. furcatus does not possess a transversely enlarged eye, but rather a slightly larger cornea and longer eye. Our results do not, however, preclude the presence of other changes in the visual system, such as retinal morphology or neurophysiology, that could be adaptive for nocturnal feeding.
Testing Williams’ prediction: reproductive effort versus residual reproductive value (RRV)
Authors: Dobson F. Stephen , Jouventin Pierre 
Published: October 2010

Williams (1966; Am. Nat. 100(916): 687–690) furthered R.A. Fisher’s concept of reproductive value by breaking it into two components: (1) current reproduction and (2) residual reproductive value (RRV, the summed product of survival and reproduction over the rest of the lifespan). He predicted a negative correlation of measures of these two components among species, and this prediction led in part to the idea of trade-offs in life-history theory. We tested Williams’ prediction with 24 species of albatrosses and petrels (order Procellariiformes), species with a great range of body sizes and all laying only one egg at a time (like humans, highly iteroparous). Two measures of reproductive investment were not negatively correlated with RRV. Adjusting data for body mass and phylogeny resulted in significant positive associations. In addition, any measure of annual parental allocation to reproduction (once adjusted for body size) should give a positive association with RRV as shown by a simple simulation model that assumes a highly iteroparous life cycle. Under such life cycles, Williams’ prediction confounds the positive influence of reproduction on both current investment and RRV. Principles of life-history theory, however, do not require re-evaluation, as this particular prediction can in at least some cases be internally inconsistent.