bluuebunny/crossref_metadata_2025_split huggingface dataset:
Altered matrix polysaccharides in cell walls of pocket galls formed by an aphid on Distylium racemosum leaves
Authors: KONNO H. , NAKATO T. , TSUMUKI H. 
Published: December 2004

ABSTRACTThe present work reports the results of a study on the isolation and characterization of matrix polysaccharides in the cell walls of galls formed by an aphid (Neothoracaphis yanonis) on Distylium racemosum leaves. Cell walls were isolated from both healthy Distylium leaf and gall tissues and then extracted sequentially with cyclohexane‐trans‐1,2‐diaminetetra‐acetate (CDTA), Na2CO3, 1 m KOH, and 4 m KOH. The amount of pectin solubilized from gall cell walls was approximately 2.6‐fold higher than the pectin solubilized from leaf cell walls, whereas the amount of hemicellulose solubilized from gall cell walls was 1.4‐fold higher than that from normal leaf cell walls. When the polysaccharides were fractionated by anion‐exchange chromatography, considerable increases in arabinose and galactose were observed in CDTA‐soluble pectic polymer (fraction PI‐1) from gall cell walls, whereas the gall cell walls had less xylose in 1 m KOH‐soluble hemicellulosic polymers (fractions HI‐2, HI‐3, and HI‐4) than did the cell walls from the healthy leaf. The hemicellulosic polymers of the gall cell walls exhibited distinctly different patterns of molecular mass, compared with the healthy leaf cell walls. These results suggest that an extensive change occurs in the matrix polysaccharide structure of the cell walls of Distylium galls formed by an aphid. In addition, many glycosylhydrolase activities were detected in the protein fraction solubilized with strong saline solution from the gall cell walls, and the activities of β‐galactosidase, β‐xylosidase and α‐l‐arabinofuranosidase were considerably increased under gall formation.
Bone mineral metabolism and histomorphometry in rats with cholestatic liver disease
Authors: Ackerman Zvi , Weinreb Miron , Amir Gail , Pollak Rivka D 
Published: December 2004

Abstract:Background: The etiology of osteopenia in cholestatic liver disease is uncertain. An animal model is needed in order to study the efficacy of therapeutic agents.Aims: In order to characterise the bone disease in rats with cholestatic liver disease.Methods: Four‐month old male Sprague–Dawley bile duct‐ligated (BDL) and sham‐operated (SO) rats were studied. Twenty‐eight days after surgery serum osteocalcin, a bone‐formation marker, urinary deoxypyridinoline (DPD) cross‐links, a resorption marker, and 25‐hydroxyvitamin D3 were determined. Static and dynamic (tetracycline‐based) histomorphometric analysis was performed on femurs and tibiae.Results: All BDL rats developed biliary cirrhosis. Bile duct‐ligated rats had lower bone mass, reflected in statistically significantly 13.5% lower femoral dry‐weight, 16% lower femoral ash‐weight, 42.7% lower tibial cancellous bone area and 19% lower trabecular thickness, compared with SO rats. Bile duct‐ligated rats exhibited decreased bone formation manifested by statistically significantly 70% lower tetracycline double‐labelling, 40% lower mineralising surface, 51% lower bone‐formation rate and 47% lower osteocalcin compared with SO rats. Deoxypyridinoline levels were 20% lower in BDL rats. Bile duct‐ligated rats had 52% lower serum 25‐hydroxyvitamin D3 level, but no significant increase in cortical osteoid area.Conclusions: Bile duct‐ligated rats develop osteopenia characterised by low bone‐formation rate, and can be used for studying therapeutic agents for patients with cholestatic liver disease displaying similar bone changes.
Generation means analysis of resistance to peanut bud necrosis caused by peanut bud necrosis tospovirus in peanut
Authors: Pensuk V. , Jogloy S. , Wongkaew S. , Patanothai A. 
Published: December 2004

AbstractThis study was conducted to evaluate the types of gene action governing the inheritance of resistance to peanut bud necrosis disease (PBND) in populations derived from three crosses involving two resistant (ICGV 86388 and IC 10) and one susceptible (KK 60–1) peanut lines. Populations were composed of P1 P2, F1 F2, BC11, BC12, BC11S and BC12S. These populations were evaluated for PBND incidence in a farmer's field in Kalasin province in north‐east Thailand, where PBND is a recurring problem. Results showed variations between crosses in the relative contributions of different types of gene effect. The results indicate that multiple genes control the PBND resistance trait, and that the two resistant lines differ in some of these genes. As non‐additive gene effects are important in all three crosses, selection for low PBND incidence in these crosses would be more effective in later generations.
A novel foraging mode in snakes: browsing by the sea snake Emydocephalus annulatus (Serpentes, Hydrophiidae)
Authors: Shine R. , Bonnet X. , Elphick M. J. , Barrott E. G. 
Published: December 2004

Summary

Ecologists often ascribe considerable importance to traits that are widespread within a specific lineage but rarely seen in other kinds of organisms. Unfortunately, such hypotheses cannot be tested robustly unless there is variation in expression of the trait within that lineage; such ‘exceptions to the rule’ provide opportunities to falsify predictions about putative functional correlates of the focal trait.
Research on snake foraging has emphasized species that feed infrequently and take large prey, often from ambush positions, but these characteristics do not apply to all snakes.
Movement patterns and feeding rates of free‐ranging Turtle‐Headed Sea Snakes Emydocephalus annulatus (Krefft 1869) were quantified in coral reefs of New Caledonia. These snakes forage by moving slowly (<2 m min−1) but consistently across the substrate as they investigate crevices and burrows for fish nests. The snakes feed frequently (sometimes, several times per hour) on large numbers of very small (1 × 0·5 mm2) eggs. Snakes weighed more than one hundred thousand times as much as the prey items (eggs) they consumed, in contrast to high relative prey masses often reported for other snake species.
Field experiments in which snakes were exposed to a variety of stimuli indicate that these animals locate their prey by scent rather than visual cues.
The foraging mode of Emydocephalus (slow continuous movement, with frequent ingestion of small, immobile, defenceless food items) is more similar to that of herbivorous browsing mammals than to that of most macrostomate snakes.
In support of published hypotheses, Emydocephalus differ from most other snakes in traits predicted to be functionally associated with ingestion of large prey.
Plasma antioxidative activity during atorvastatin and fluvastatin therapy used in coronary heart disease primary prevention
Authors: Kowalski Jan , Pawlicki Lucjan , Grycewicz Joanna , Błaszczyk Jan , Irzmański Robert , Cegliński Tomasz , Kowalczyk Edward 
Published: December 2004

AbstractWe estimated the effect of atorvastatin and fluvastatin on plasma antioxidative activity used in coronary heart disease (CHD) primary prevention. Anti‐oxidative activity of blood plasma was determined by Bartosz et al. method [Curr. Top. Biophys. (1998)22:11–13], based on reduction of preformed cation radical of 2,2,azinobis(3‐ethylbenzothiazoline‐6‐sulphonic acid) by blood plasma. The study comprised 35 patients with CHD risk who were randomly divided into two groups. The atorvastatin group comprised 17 patients who were administered the drug orally in a daily dose of 10 mg and the fluvastatin group consisted of 18 patients on an oral dose of 40 mg once daily. The control group comprised 12 healthy subjects with no drug administration. Blood samples were collected from cubital vein before and after 6‐week therapy. Significantly (P < 0.05) increased – in comparison with the initial values – antioxidative activity of blood plasma was found in atorvastatin and fluvastatin groups after 6‐week therapy. Moreover, the increase in antioxidative plasma activity in atorvastatin group was significantly higher in comparison with the fluvastatin group. The results of our study have demonstrated that atorvastatin and fluvastatin have an additional mechanism independent of the effect on cholesterol concentration. Thus, we presume that administration of these statins in CHD risk patients may have a beneficial effect.
Correlation of nitrites in breath condensates and lung function in asthmatic children
Authors: Straub Daniel A. , Ehmann Rainer , Hall Graham L. , Mœller Alexander , Hamacher Jürg , Frey Urs , Sennhauser Felix H. , Wildhaber Johannes H. 
Published: December 2004

We aimed to evaluate the value of exhaled breath condensates in monitoring airway inflammation in childhood asthma before and after high altitude climate therapy.Forty‐eight asthmatic children on regular anti‐asthma treatment with a normal FEV1and positive skin prick test for house dust mites were recruited. All children had been referred to an alpine clinic for high altitude climate therapy, because of persistent asthmatic symptoms despite use of daily anti‐inflammatory treatment. Subjects were assessed on their arrival and before departure from the alpine clinic. Spirometry, bronchial provocation tests and measurements of nitrites in breath condensates were performed.Median levels of nitrites were significantly higher before than after high altitude climate therapy (1.27 vs. 0.93 μm; p = 0.008). In addition, MEF50improved significantly (p < 0.0005). There was a significant correlation between nitrites in breath condensates and MEF50(r = −0.63, p < 0.0001), symptoms (r = 0.47, p = 0.0007) and airway hyper‐reactivity (AHR) (r = −0.41, p = 0.004).In summary, we found a reduction in nitrites in breath condensates after a high altitude climate therapy. Significant correlations were found between nitrites and MEF50, AHR and symptoms. We conclude that the measurement of nitrites may be feasible to objectively assess airway inflammation in asthmatic children in order to detect ongoing inflammation in children with normal FEV1but persistent symptoms.
Commercial fishing in the Brazilian Amazon: regional differentiation in fleet characteristics and efficiency
Authors: Almeida O. T. , Lorenzen K. , Mcgrath D. G. 
Published: December 2004

AbstractRegional differentiation in fleet characteristics and economic efficiency, as well as the total elasticity of scale in the commercial fishing fleets of the Brazilian Amazon were analysed. Data were collected in 893 interviews with boat operators in four major ports on the River Amazon. Boats operating from the largest cities (Belém and Manaus) are mostly operated by hired skippers and non‐permanent crews, while boats from smaller cities (Santarém and Tefé) are mostly owner‐operated and use permanent crews. In the lower Amazon, a large proportion of fishermen (89% in Santarém and 53% in Belém) are based in rural areas, while in the upper Amazon commercial fishermen are predominantly urban‐based. A production function analysis identified boat length, gear type used (gill net/purse seine), number of fishermen employed, quantities of fuel and ice used, and education level of the skipper as significant factors determining the catch. The analysis provided no evidence of regional differences in stock levels. The use of purse seines was associated with significantly higher catches (by 32%), all other factors being equal. Purse seines are banned in the lower Amazon (Santarem and Belem), and this results in overall lower levels of technical efficiency in this region. No significant total scale effect on efficiency was detected. These results are discussed with respect to the institutional sustainability of current fisheries co‐management initiatives.
Variation in thermal tolerance is linked to phosphoglucose isomerase genotype in a montane leaf beetle
Authors: Neargarder G. , Dahlhoff E. P. , Rank N. E. 
Published: December 2004

SummarySierra Nevada populations of the Willow BeetleChrysomela aeneicollis(Schaeffer) experience extreme elevated and subzero temperatures in nature. In these populations, frequencies of phosphoglucose isomerase (PGI) alleles vary with latitude and altitude and respond to climate change. PGI genotypes differ in expression of a stress‐inducible heat shock protein (Hsp70).Here, differences in tolerance of elevated and subzero extreme temperatures were compared for field‐acclimatized and laboratory‐acclimated larvae and adults possessing three common PGI genotypes (PGI 1–1, 1–4 and 4–4). Three indices of thermal tolerance were measured – CTmax, LT50and Hsp70 expression level.Thermal tolerance depended on life stage, prior exposure to sublethal stress and PGI genotype. Larvae were generally less tolerant of thermal extremes than adults. For both adults and larvae, prior exposure to sublethal temperatures increased survival after exposure to subsequent stress. Survival after exposure to thermal extremes was consistently related to PGI genotype (1–1 > 1–4 > 4–4), as were expression levels of Hsp70 (1–1 > 1–4 > 4–4).These results suggest that PGI genotypes differ in tolerance of thermal extremes routinely experienced by beetles in nature. A trade‐off between thermal tolerance and energy allocation may explain the persistence of the PGI polymorphism.
Fate of DNA replication fork encountering a single DNA lesion during oriC plasmid DNA replication in vitro
Authors: Higuchi Kumiko , Katayama Tsutomu , Iwai Shigenori , Hidaka Masumi , Horiuchi Takashi , Maki Hisaji 
Published: December 2004

AbstractBackground: The inhibition of DNA replication fork progression by DNA lesions can lead to cell death or genome instability. However, little is known about how such DNA lesions affect the concurrent synthesis of leading‐ and lagging‐strand DNA catalysed by the protein machinery used in chromosomal replication. Using a system of semi‐bidirectional DNA replication of an oriC plasmid that employs purified replicative enzymes and a replication‐terminating protein of Escherichia coli, we examined the dynamics of the replication fork when it encounters a single abasic DNA lesion on the template DNA.Results: A DNA lesion located on the lagging strand completely blocked the synthesis of the Okazaki fragment extending toward the lesion site, but did not affect the progression of the replication fork or leading‐strand DNA synthesis. In contrast, a DNA lesion on the leading strand stalled the replication fork in conjunction with strongly inhibiting leading‐strand synthesis. However, about two‐thirds of the replication forks encountering this lesion maintained lagging‐strand synthesis for about 1 kb beyond the lesion site, and the velocity with which the replication fork progressed seemed to be significantly reduced.Conclusions: The blocking DNA lesion affects DNA replication differently depending on which strand, leading or lagging, contains the lesion.
Cdc42 and Rac small G proteins activated by trans‐interactions of nectins are involved in activation of c‐Jun N‐terminal kinase, but not in association of nectins and cadherin to form adherens junctions, in fibroblasts
Authors: Honda Tomoyuki , Shimizu Kazuya , Kawakatsu Tomomi , Fukuhara Atsunori , Irie Kenji , Nakamura Takeshi , Matsuda Michiyuki , Takai Yoshimi 
Published: December 2004

AbstractBackground: Nectins are Ca2+‐independent immunoglobulin‐like cell‐cell adhesion molecules which associate with cadherins to form adherens junctions (AJs) in epithelial cells and fibroblasts. Nectin‐1 and ‐3 are members of the nectin family which most strongly trans‐interact, causing cell‐cell adhesion. The trans‐interaction between nectin‐1 and ‐3 induces the activation of both Cdc42 and Rac small G proteins in epithelial cells. We studied the roles of Cdc42 and Rac activated in this way in L fibroblasts stably expressing both nectin‐1 and E‐cadherin (nectin‐1‐EL cells).Results: The trans‐interaction between nectin‐1 and ‐3 induced the activation of Cdc42 and Rac in nectin‐1‐EL cells. Cdc42, and presumably Rac, activated in this way, induced the activation of c‐Jun N‐terminal kinase (JNK), but not p38 mitogen‐activated protein (MAP) kinase or extracellular signal‐regulated kinase (ERK). Cdc42 or Rac was not essential for the association of nectin‐1 and E‐cadherin to form AJs. Reorganization of the actin cytoskeleton was not required for the association of nectin‐1 and E‐cadherin.Conclusion: These results indicate that Cdc42 and Rac activated by the trans‐interaction of nectins selectively induce the activation of JNK, but are not essential for the association of nectins and cadherin to form AJs in fibroblasts.
GATA‐1 testis activation region is essential for Sertoli cell‐specific expression of GATA‐1 gene in transgenic mouse
Authors: Wakabayashi Junko , Yomogida Kentaro , Nakajima Osamu , Yoh Keigyou , Takahashi Satoru , Engel James Douglas , Ohneda Kinuko , Yamamoto Masayuki 
Published: December 2004

AbstractBackground: The erythroid transcription factor GATA‐1 is also expressed in Sertoli cells of the testis. The testicular expression of GATA‐1 is regulated in a developmental and spermatogenic stage‐specific manner. To further clarify the regulatory mechanisms of testicular GATA‐1 gene expression, we carried out transgenic reporter gene expression analyses.Results: We found that GATA‐1 expression in Sertoli cells is markedly decreased concomitant with the emergence of elongated spermatids in the seminiferous tubules. Transgenic reporter mouse analyses revealed that a 15 kb GATA‐1 genomic region is sufficient to recapitulate the gene expression profile in Sertoli cells. While the GATA‐1 haematopoietic enhancer and the proximal first exon are included within the 15 kb genomic region, these regulatory elements are not essential for GATA‐1 expression in Sertoli cells. Further analyses using deletion constructs revealed that a 1.5 kb region 5′ to the GATA‐1 haematopoietic enhancer is essential for gene expression in Sertoli cells and this region is referred to as the GATA‐1 testis activation region.Conclusion: These results thus demonstrated that the GATA‐1 testis activation region is essential for Sertoli cell‐specific expression of GATA‐1 gene. The 15 kb genomic region is applicable and useful for the expression vector system specific for adult Sertoli cells in stage VII to IX.
Response of terrestrial carbon uptake to climate interannual variability in China
Authors: CAO MINGKUI , PRINCE STEPHEN D. , LI KERANG , TAO BO , SMALL JENNIFER , SHAO XUEMEI 
Published: December 2004

AbstractThe interest in national terrestrial ecosystem carbon budgets has been increasing because the Kyoto Protocol has included some terrestrial carbon sinks in a legally binding framework for controlling greenhouse gases emissions. Accurate quantification of the terrestrial carbon sink must account the interannual variations associated with climate variability and change. This study used a process‐based biogeochemical model and a remote sensing‐based production efficiency model to estimate the variations in net primary production (NPP), soil heterotrophic respiration (HR), and net ecosystem production (NEP) caused by climate variability and atmospheric CO2 increases in China during the period 1981–2000. The results show that China's terrestrial NPP varied between 2.86 and 3.37 Gt C yr−1 with a growth rate of 0.32% year−1 and HR varied between 2.89 and 3.21 Gt C yr−1 with a growth rate of 0.40% year−1 in the period 1981–1998. Whereas the increases in HR were related mainly to warming, the increases in NPP were attributed to increases in precipitation and atmospheric CO2. Net ecosystem production (NEP) varied between −0.32 and 0.25 Gt C yr−1 with a mean value of 0.07 Gt C yr−1, leading to carbon accumulation of 0.79 Gt in vegetation and 0.43 Gt in soils during the period. To the interannual variations in NEP changes in NPP contributed more than HR in arid northern China but less in moist southern China. NEP had no a statistically significant trend, but the mean annual NEP for the 1990s was lower than for the 1980s as the increases in NEP in southern China were offset by the decreases in northern China. These estimates indicate that China's terrestrial ecosystems were taking up carbon but the capacity was undermined by the ongoing climate change. The estimated NEP related to climate variation and atmospheric CO2 increases may account for from 40 to 80% to the total terrestrial carbon sink in China.
The catchment and climate regulation of pCO2 in boreal lakes
Authors: SOBEK SEBASTIAN , ALGESTEN GRETE , BERGSTRÖM ANN‐KRISTIN , JANSSON MATS , TRANVIK LARS J. 
Published: December 2004

AbstractThe regulation of surface water pCO2 was studied in a set of 33 unproductive boreal lakes of different humic content, situated along a latitudinal gradient (57°N to 64°N) in Sweden. The lakes were sampled four times during one year, and analyzed on a wide variety of water chemistry parameters. With only one exception, all lakes were supersaturated with CO2 with respect to the atmosphere at all sampling occasions. pCO2 was closely related to the DOC concentration in lakes, which in turn was mainly regulated by catchment characteristics. This pattern was similar along the latitudinal gradient and at different seasons of the year, indicating that it is valid for a variety of climatic conditions within the boreal forest zone. We suggest that landscape characteristics determine the accumulation and subsequent supply of allochthonous organic matter from boreal catchments to lakes, which in turn results in boreal lakes becoming net sources of atmospheric CO2.
Effects of elevated CO2 on the size structure in even‐aged monospecific stands of Chenopodium album
Authors: NAGASHIMA HISAE , YAMANO TAKASHI , HIKOSAKA KOUKI , HIROSE TADAKI 
Published: December 2004

AbstractTo investigate the effect of elevated CO2 on the size inequality and size structure, even‐aged monospecific stands of an annual, Chenopodium album, were established at ambient and doubled CO2 with high and low nutrient availabilities in open top chambers. The growth of individual plants was monitored non‐destructively every week until flowering. Elevated CO2 significantly enhanced plant growth at high nutrients, but did not at low nutrients. The size inequality expressed as the coefficient of variation tended to increase at elevated CO2. Size structure of the stands was analyzed by the cumulative frequency distribution of plant size. At early stages of plant growth, CO2 elevation benefited all individuals and shifted the whole size distribution of the stand to large size classes. At later stages, dominant individuals were still larger at elevated than at ambient CO2, but the difference in small subordinate individuals between two CO2 levels became smaller. Although these tendencies were found at both nutrient availabilities, difference in size distribution between CO2 levels was larger at high nutrients. The CO2 elevation did not significantly enhance the growth rate as a function of plant size except for the high nutrient stand at the earliest stage, indicating that the higher biomass at elevated CO2 at later stages in the high nutrient stand was caused by the larger size of individuals at the earliest stage. Thus the effect of elevated CO2 on stand structure and size inequality strongly depended on the growth stage and nutrient availabilities.
Climatic trends and advancing spring flight of butterflies in lowland California
Authors: FORISTER MATTHEW L. , SHAPIRO ARTHUR M. 
Published: December 2004

AbstractMany studies, largely from cool‐temperate latitudes, have investigated the relationship between the timing of biological events and changes in climatic conditions during the past few decades. Relatively little is known about the response of plants and animals at lower latitudes. Here we show that the average first spring flight of 23 butterfly species in the Central Valley of California has advanced to an earlier date over the past 31 years. Among the species that have appeared significantly earlier, the average shift is 24 days. Climatic conditions (largely winter temperature and precipitation) are found to explain a large part of the variation in changing date of first flight. These results suggest a strong ecological influence of changing climatic conditions on a suite of animals from a mid‐latitude, Mediterranean climate.