bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of drying conditions on wettability and DRIFT spectroscopic C–H band of soil samples
Authors: Diehl D. , Ellerbrock R. H. , Schaumann G. E. 
Published: June 2009

SummaryThis study assesses the effect of various drying procedures on water repellency measured by water drop penetration time (WDPT) and spectroscopic parameters gauged by Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFT) of two anthropogenically‐influenced soils at sites in Berlin. Wettable and water‐repellent samples were dried at various temperatures and at prescribed relative humidity. WDPT and DRIFT spectroscopic characteristics were obtained from both dried and field‐moist subsamples. Normalization of DRIFT spectral C–H band intensity (‘surface hydrophobicity’) against the integral absorption intensity over the wave number range 4000–400 cm−1 resulted in an apparent resolution between the effects of water content and changes in C‐H absorption at the surface. To our current knowledge, the latter could be best explained with changes in the three‐dimensional rearrangement of organic molecules or moieties on inner and outer soil organic matter (SOM) surfaces, whereas the former could be a direct consequence of the fraction of inner and outer soil surfaces covered with water and of the mean thickness of the respective water films. Further evidence for this model is required from other investigations focusing on the surfaces in soil, before drawing final conclusions. The results show that the method of drying affects WDPT to a greater extent than soil water content after drying. DRIFT spectra suggest that exposure to high temperature results in some reorganization of SOM in the outer layer. It is further suggested that short exposure may result in a heterogeneous distribution of water leading to localized variation and inconsistency in WDPTs. Drying for 4 weeks under controlled relative humidity at 20°C is suggested as a reference preparation method combining the benefits of an almost unchanged SOM surface compared with field‐moist samples with homogeneous moisture distribution.
Microbial leaf degraders in boreal streams: bringing together stochastic and deterministic regulators of community composition
Authors: FISCHER HELMUT , BERGFUR JENNY , GOEDKOOP WILLEM , TRANVIK LARS 
Published: June 2009

Summary1. Leaves that fall into the water represent a new habitat for microorganisms to colonise in streams, providing an opportunity to study colonisation and the subsequent regulation of community structure. We explored community composition of bacteria and fungi on decomposing alder leaves in nine streams in central Sweden, and describe their relationship with environmental variables. Succession of the microbial community was studied in one of the streams for 118 days. Microbial community composition was examined by denaturing gradient gel electrophoresis on replicate samples of leaves from each stream.2. During succession in one stream, maximum taxon richness was reached after 34 days for bacteria and 20 days for fungi respectively. Replicate samples within this stream differed between each other earlier in colonisation, while subsequently such variation among replicate communities was low and remained stable for several weeks. Replicate samples taken from all the nine streams after 34 days of succession showed striking similarities in microbial communities within‐streams, although communities differed more strongly between streams.3. Canonical analysis of microbial communities and environmental variables revealed that water chemistry had a significant influence on community composition. This influence was superimposed on a statistical relationship between the properties of stream catchments and microbial community composition.4. The catchment regulates microbial communities in two different ways. It harbours the species pool from which the in‐stream microbial community is drawn and it governs stream chemistry and the composition of organic substrates that further shape the communities. We suggest that there is a random element to colonisation early in succession, whereas other factors such as species interactions, stream chemistry and organic substrate properties, result in a more deterministic regulation of communities during later stages.
Phylogeography of the cactophilic species Drosophila gouveai: demographic events and divergence timing in dry vegetation enclaves in eastern Brazil
Authors: Moraes Evandro M. , Yotoko Karla S. C. , Manfrin Maura H. , Solferini Vera N. , Sene Fábio M. 
Published: June 2009

AbstractAim  The aim of this study was to assess the causal mechanisms underlying populational subdivision in Drosophila gouveai, a cactophilic species associated with xeric vegetation enclaves in eastern Brazil. A secondary aim was to investigate the genetic effects of Pleistocene climatic fluctuations on these environments.Location  Dry vegetation enclaves within the limits of the Cerrado domain in eastern Brazil.Methods  We determined the mitochondrial DNA haplotypes of 55 individuals (representing 12 populations) based on sequence data of a 483‐bp fragment from the cytochrome c oxidase subunit II (COII) gene. Phylogenetic and coalescent analyses were used to test for the occurrence of demographic events and to infer the time of divergence amongst genetically independent groups.Results  Our analyses revealed the existence of two divergent subclades (G1 and G2) plus an introgressed clade restricted to the southernmost range of D. gouveai. Subclades G1 and G2 displayed genetic footprints of range expansion and segregated geographical distributions in south‐eastern and some central highland regions, east and west of the Paraná River valley. Molecular dating indicated that the main demographic and diversification events occurred in the late to middle Pleistocene.Main conclusions  The phylogeographical and genetic patterns observed for D. gouveai in this study are consistent with changes in the distribution of dry vegetation in eastern Brazil. All of the estimates obtained by molecular dating indicate that range expansion and isolation pre‐dated the Last Glacial Maximum, occurring during the late to middle Pleistocene, and were probably triggered by climatic changes during the Pleistocene. The current patchy geographical distribution and population subdivision in D. gouveai is apparently closely linked to these past events.
The relationship between marine fronts and fish diversity in the Patagonian Shelf Large Marine Ecosystem
Authors: Alemany D. , Acha E. M. , Iribarne O. 
Published: June 2009

AbstractAim  To evaluate the relationship between marine fronts and (1) fish diversity patterns, (2) fish biomass distribution, and (3) fish assemblage structure.Location  Patagonian Shelf, Southwestern Atlantic Ocean.Methods  Three main frontal systems and eight nearby zones (frontal vs. non‐frontal areas) were compared. An extensive fishery database, obtained during an a priori sampling scheme (spatial resolution 1 × 1) from 1978 to 1979, was employed. Analyses of 248 trawling stations were performed using a combination of diversity measures (species richness, Shannon diversity and evenness), biomass analyses and multivariate analyses [nonparametric analysis of similarity (ANOSIM), non‐metric multidimensional scaling ordination (NMDS) and similarity percentages (SIMPER)] to evaluate the effect of fronts on fish communities.Results  In total, 46 fish taxa were identified. Demersal fish diversity increased at the tidal front of Península Valdés but decreased in the frontal zones of the Southern Shelf‐Break and Magellan frontal systems. The richness and biomass of pelagic fish were higher at the Península Valdés Tidal Front, while the biomass of demersal fish was higher at its non‐frontal counterpart. Fish diversity did not differ consistently along the Northern Shelf‐Break Front. However, a higher fish biomass was registered at the non‐frontal zone. Demersal and pelagic fish assemblages differed between frontal and non‐frontal zones.Main conclusions  The Patagonian Shelf Large Marine Ecosystem has diverse frontal types that appear to have different effects on fish diversity and assemblage structure. Seasonal (tidal) or permanent fronts have different effects on the parameters analysed, which could be due to productivity–diversity relationships. The Península Valdés Tidal Front, a relatively short temporal scale system, demonstrates a stronger influence on fish diversity, biomass and assemblage structure than the other frontal areas studied. The seasonality of nutrient input owing to frontogenesis, which begins during the austral spring, may play an important role in determining local diversity. At permanent frontal features, diversity decreases when the nutrient availability is high. This is potentially because, when food resources increase, a few species become dominant.
Molecular evidence for Gondwanan origins of multiple lineages within a diverse Australasian gecko radiation
Authors: Oliver Paul M. , Sanders Kate L. 
Published: June 2009

AbstractAim  Gondwanan lineages are a prominent component of the Australian terrestrial biota. However, most squamate (lizard and snake) lineages in Australia appear to be derived from relatively recent dispersal from Asia (< 30 Ma) and in situ diversification, subsequent to the isolation of Australia from other Gondwanan landmasses. We test the hypothesis that the Australian radiation of diplodactyloid geckos (families Carphodactylidae, Diplodactylidae and Pygopodidae), in contrast to other endemic squamate groups, has a Gondwanan origin and comprises multiple lineages that originated before the separation of Australia from Antarctica.Location  Australasia.Methods  Bayesian (beast) and penalized likelihood rate smoothing (PLRS) (r8s) molecular dating methods and two long nuclear DNA sequences (RAG‐1 and c‐mos) were used to estimate a timeframe for divergence events among 18 genera and 30 species of Australian diplodactyloids.Results  At least five lineages of Australian diplodactyloid geckos are estimated to have originated > 34 Ma (pre‐Oligocene) and basal splits among the Australian diplodactyloids occurred c. 70 Ma. However, most extant generic and intergeneric diversity within diplodactyloid lineages appears to post‐date the late Oligocene (< 30 Ma).Main conclusions  Basal divergences within the diplodactyloids significantly pre‐date the final break‐up of East Gondwana, indicating that the group is one of the most ancient extant endemic vertebrate radiations east of Wallace’s Line. At least five Australian lineages of diplodactyloid gecko are each as old or older than other well‐dated Australian squamate radiations (e.g. elapid snakes and agamids). The limbless Pygopodidae (morphologically the most aberrant living geckos) appears to have radiated before Australia was occupied by potential ecological analogues. However, in spite of the great age of the diplodactyloid radiation, most extant diversity appears to be of relatively recent origin, a pattern that is shared with other Australian squamate lineages.
Asynchronous online discussion thread development: examining growth patterns and peer‐facilitation techniques
Authors: Chan J.C.C. , Hew K.F. , Cheung W.S. 
Published: June 2009

AbstractThis study extends the research on asynchronous online discussion (AOD) by providing a perspective on: (1) the growth patterns of discussion threads and (2) the influence of peer‐ or student‐facilitation techniques on thread development. Using the Pointing, Questioning, Resolving and Summarizing (PQRS) facilitation techniques framework, the threaded discussions of seven AOD forums were carefully mapped out and each message in the postings was examined to determine the type of facilitation techniques applied. Results suggest that an online discussion thread grows either one of three patterns: a ‘short thread pattern’, an ‘extended thread pattern’ with an elongated structure or a ‘split thread pattern’ with a broad structure. Results also suggest that the use of Resolving and Summarizing facilitation techniques tends to foster early thread termination. Understanding how each PQRS student‐facilitation technique impacts thread development reinforces the need to combine the use of ‘questioning’ techniques with other facilitation techniques to enhance thread continuity. We end by discussing some possible implications and issues for future research.
Correlation of visual function with health‐related quality of life in glaucoma patients
Authors: Lin Jen‐Chieh , Yang Ming‐Chin 
Published: June 2009

AbstractObjectives  The purpose of this study was to assess visual impairment and quality of life (QOL), the relationship between visual function and health‐related and vision‐related QOL, and to identify factors significantly impacting QOL for glaucoma patients.Methods  One‐on‐one interviews of 280 glaucoma patients at a regional hospital in Taiwan from 1 April 2005 to 30 September 2005. Data collected included demographics, clinical examinations and treatment status. QOL data collected utilized the Chinese (Taiwanese) version of the Medical Outcomes Study Short‐Form 36 Health Survey (SF‐36) and the National Eye Institute Visual Function‐25 (NEIVFQ‐25).Results  The majority of study participants had open‐angle glaucoma (54.3%) and were classified as moderate stage (33.6%). The higher the health‐related QOL scores for both questionnaires, the fewer difficulties experienced by the patients. Moderate correlation was found between the SF‐36 and NEIVFQ‐25 subscales and visual function. Significant predicting factors for the SF‐36 were gender, age, employment status, presence of systemic disease, better‐eye visual acuity and better‐eye mean defect. For the NEIVFQ‐25, these were general vision, near and distance activities, colour vision and peripheral vision scores.Conclusions  A combination of demographic data, clinical examination and QOL questionnaires may help clinicians better ascertain the impact of disease severity on glaucoma patients' QOL. This information may help in patient education, treatment compliance and selection of treatment options.
Serum lipoproteins in plasma lecithin:cholesterol acyltransferase deficiency, studied by electron microscopy
Authors: Torsvik H. , Solaas Marit Hornberg , Gjone E. 
Published: June 2009

Serum lipoproteins from a patient with LCAT deficiency have been studied by electron microscopy and compared with lipoproteins from a normal individual and a patient with hyperlipo‐proteinemia of type IV. Particles of density < 1.006 g/ml from the LCAT deficiency patient were within a range of 230–3000 Å in diameter, whereas the diameters of the corresponding particles from the other two subjects fell within a range from 230 to 900 Å. A mean diameter of approximately 200 Å was found for the low density lipoproteins (l.019–1.063 g/ml) from the three subjects investigated.In LCAT deficiency the high density lipoprotein (1.063–1.195 g/ml) particles demonstrated a tendency to rouleau‐formation, giving the molecules a coinlike appearance with a mean diameter of 162 Å, and a mean thickness of 46 Å. In electron micrographs of HDL particles from the other two subjects studied, rouleau‐formation was not observed, and the mean diameters were of 82 and 85 Å, respectively.By gel filtration on Sephadex G‐200 of the HDL fraction from the patient with LCAT deficiency two populations of particles were found, one with a mean particle diameter of 163 Å and one with particle diameters of 35–56 Å.
Do the 48, XXYY males have a characteristic phenotype? A Review
Authors: Borgaonkar Digamber S. , Mules Emilie , Char Florence. 
Published: June 2009

Data on fifty‐three patients with 48, XXYY chromosome complement were collected from the literature and personal correspondence and reviewed with the objective of delineating a ‘uniform phenotype.’ Although no single stigma was found to be characteristic of the 48, XXYY males, tall stature, low upper segment/lower segment ratio, mental retardation, and behavior problems in a phenotypic male (including prepubertal age group) should raise the question of a 48, XXYY chromosome basic defect. In the majority of cases testicular biopsies revealed varying degrees of atrophy, levels of FSH were elevated, and 17 KS were low to normal, both characteristics being comparable to those found in 47, XXY males.Dermatoglyphic changes were found to be reduced total finger ridge count, increased frequency of arches on fingers, presence of a hypothenar pattern, distally placed triradius, and occasional qimian crease.
Further studies on serum α1‐lipoprotein in familial lecithin:cholesterol acyltransferase deficiency
Authors: Torsvik Harald 
Published: June 2009

Serum high density lipoprotein (HDL) from two patients with LCAT deficiency has been compared with HDL from normal subjects and HDL from a presumed heterozygous carrier. By two different immunological methods the concentration of ‐lipoprotein in serum of the patients was found to he about 25–30 % of the normal concentration.Patient HDL is cornpoked of two fractions, as shown previously. The first fraction contains particles of high molecular weight with an electrophoretic mobility slightly slower than that of normal HDL. The lipid content is 70%, and the concentrations of unesterified cholesterol and phospholipids are about 10–15 and 3–4 times that of normal HDL, respectively. The second fraction consists of particles of relatively low molecular weight with electrophoretic mobility faster than albumin. This fraction exhibits closc to normal concentrations of unesterified cholesterol and phospholipids. Esterified cholesterol or lysolccithin could he demonstrated in none of the fractions.HDL from the prewmed hetcrozygous carrier was normal as judged from immunoelectro‐phoresis, gel filtration, electron microscopy. and lipid analyses.
Selective Absorption of K over Na in Sugar Beet Cultivars and its Relationship with Yield and Quality in Two Contrasting Environments of Central Greece
Authors: Tsialtas J. T. , Maslaris N. 
Published: June 2009

AbstractSelective absorption (SA) of K over Na (i.e. the preferential absorption of K over Na) has been proposed as a Na tolerance mechanism but genotypic variation for this trait has not been assessed with sugar beet in the field. Thus, the aim of this study was to explore the variation of SA in 14 sugar beet cultivars and to relate SA with yield and root quality in two sites of central Greece (Amfithea and Pyrgetos). Genotypic variation for SA was significant and the SA values were higher in Pyrgetos, the site with the lower soil K and Na concentrations. In Pyrgetos, a favourable environment for sugar beet growth, cultivars yielded more and root quality was better. In that site, a negative relationship between SA and yield (fresh root weight, sugar yield) was found indicating that strong Na exclusion from root is a disadvantage for high yielding. Negative SA–yield relationships were evident in Amfithea when five cultivars with very low SA values (<1.00) were excluded from the analysis. Combined all the cultivars, curvilinear functions were the best‐fitted curves for the SA–yield relationships. In Amfithea, where sugar beets had lower water content in root (WCR), a significant, positive correlation between SA and % sucrose content in fresh root weight was found. This finding was ascribed to the dilution of sucrose in roots due to the increased WCR as a result of the increased root Na concentration. In both sites, SA was positively related with root K concentration and negatively with Na concentration. The positive correlations between SA and root α‐amino N concentration indicated that sugar beet N nutrition could be affected by the genotypic ability to exclude Na from the root.
Effects of Water Shortage and Air Temperature on Seed Yield and Seed Performance of Lucerne (Medicago sativa L.) in a Mediterranean Environment
Authors: Karamanos A. J. , Papastylianou P. T. , Stavrou J. , Avgoulas C. 
Published: June 2009

AbstractSeed production and performance of lucerne is characterized by fluctuating yields with often poor seed quality, and is dependent on environmental conditions, genetic characteristics and agronomic techniques applied during seed set, development, maturation and storage. A field experiment was carried out in two successive growing seasons at Kopais (southern Greece) to evaluate the effects of drought stress imposed by three irrigation treatments, and temperature during flowering and seed filling on lucerne seed yield and quality. Plant water status, expressed in terms of the water potential index (WPI), growth in leaf area and dry weight, seed yield and yield components, flowering and seed quality parameters were measured throughout the growing seasons. The adopted irrigation schemes produced a clear differentiation among treatments concerning their plant water status. Seed yield and leaf growth showed close positive correlations with WPI. An irrigation effect was also detected for the number of pods/plant, but not for the average weight of seeds/pod. Less negative values of WPI, and, especially, higher temperatures during flowering were also positively associated with a longer duration of flowering, as well as with higher total numbers of inflorescences. A very good description of the time course of seed germination was performed by fitting the Richards’ function to the real data. By examining the germination parameters derived from this function it was found that final germination and germination rate were improved, while germination duration was shortened with more negative values of WPI. The effects of growing season and seeding period were occasionally equally or more important than irrigation effects. These results are also discussed in terms of their practical implications for seed producing lucerne crops.
Influence of inclusion size on S‐N curve characteristics of high‐strength steels in the giga‐cycle fatigue regime
Authors: LU L. T. , ZHANG J. W. , SHIOZAWA K. 
Published: June 2009

ABSTRACTFatigue fracture of high‐strength steels often occurs from small defect on the surface of a material or from non‐metallic inclusion in the subsurface zone of a material. Under rotating bending loading, the S‐N curve of high‐strength steels consists of two curves corresponding to surface defect‐induced fracture and internal inclusion‐induced fracture. The surface defect‐induced fracture occurs at high stress amplitude levels and low cycles. However, the subsurface inclusion‐induced fracture occurs at low stress amplitude levels and high‐cycle region of more than 106 cycles (giga‐cycle fatigue life). There is a definite stress range in the S‐N curve obtained from the rotating bending, where the crack initiation site changes from surface to subsurface, giving a stepwise S‐N curve or a duplex S‐N curve. On the other hand, under cyclic axial loading, the S‐N curve of high‐strength steels displays a continuous decline and surface defect‐induced or internal inclusion‐induced fracture occur in the whole range of amplitudes. In this paper, influence factors on S‐N curve characteristics of high‐strength steels, including size of inclusions and the stress gradient of bending fatigue, were investigated for rotating bending and cyclic axial loading in the giga‐cycle fatigue regime. Then, based on the estimated subsurface crack growth rate from the S‐N data, effect of inclusion size on the dispersion of fatigue life was explained, and it was clarified that the shape of S‐N curve for subsurface inclusion‐induced fracture depends on the inclusion size.