bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of nitrogen mineralization in young humic fractions by anaerobic decomposition of rice crop residues
Authors: Olk D. C. , Samson M. I. , Gapas P. 
Published: July 2006

SummaryField observations indicate a long‐term decrease in crop uptake of N derived from soil organic matter under continuous production of irrigated lowland rice (Oryza sativa L.). Decreased availability has been associated with an accumulation of phenolic lignin residues in soil organic matter, which can chemically bind N. To evaluate the hypothesis that the decrease in N availability results primarily from anaerobic decomposition of incorporated crop residues, 15N‐labelled fertilizer was applied three times during one growing season in a field study that compared anaerobic decomposition with aerobic decomposition for annual rotations of rice (Oryza sativa L.)–rice and rice–maize (Zea mays L.). Contents of 15N and total N during the growing season were measured in humic fractions and total soil organic matter. Results indicated an inhibition of N mineralization for the rice–rice rotation with anaerobic decomposition of crop residues, both for 15N that was immobilized after application and for total N. The inhibition was strongest for 15N that was applied at planting. It became more evident as the season progressed and reached significant levels during mid‐season stages of plant growth when crop demand for N peaks. These results were clearest for a young, phenolic‐rich humic fraction that was active in 15N immobilization and remineralization. Comparable but less significant trends were evident for a more recalcitrant humic fraction and for soil organic matter. Trends in crop‐N uptake associated the combination of rice–rice rotation and anaerobic decomposition with inhibited uptake of soil organic N but uninhibited uptake of fertilizer N. Increased aeration of rice soils through aerobic decomposition of crop residues or crop rotation is a promising management technique for improving soil N supply in lowland rice cropping.
Adsorption of phthalic acid and salicylic acid by two variable charge soils as influenced by sulphate and phosphate
Authors: Xu R. K. , Xiao S. C. , Zhang H. , Jiang J. , Ji G. L. 
Published: July 2006

SummaryLow‐molecular‐weight (LMW) organic acids exist widely in soils, especially in the rhizosphere, and the adsorption of these acids may affect their reactions in soils. The adsorption behaviour of phthalic acid and salicylic acid by two variable charge soils (a Rhodic Ferralsol and a Haplic Acrisol) was investigated. Both soils exhibited great adsorption capacity for these organic acids, with a greater affinity for phthalic acid. The Rhodic Ferralsol adsorbed more organic acids of both kinds than the Haplic Acrisol, which was consistent with the content of iron and aluminum oxides in the two soils. The iron oxides in these soils played a significant role in adsorption of the organic acids, whilst the soil aluminosilicate minerals, such as kaolinite, showed a small adsorption capacity. The presence of phosphate and sulphate caused a decrease in the adsorption of both organic acids because of their competition with them for sorption sites. The phosphate showed a bigger inhibition on the adsorption than sulphate as a result of a greater amount of phosphate adsorbed by the soils. The adsorption of both organic acids was affected by pH only slightly at pH < 4.5. However, the adsorption decreased with the increase in pH at pH > 4.5. A similar trend was observed for the phosphate system, but the opposite was seen for the sulphate system. This suggests that the inhibition of sulphate on the adsorption of the organic acids decreased with the increase in pH, because the adsorption of sulphate decreased strongly with increasing pH.
Are serum adiponectin concentrations in a population sample of 64‐year‐old Caucasian women with varying glucose tolerance associated with ultrasound‐assessed atherosclerosis?
Authors: BEHRE C. J. , BROHALL G. , HULTHE J. , WIKSTRAND J. , FAGERBERG B. 
Published: July 2006

Abstract.Objective.  To examine whether serum adiponectin concentrations were associated with subclinical atherosclerosis assessed as intima media thickness (IMT) in the carotid arteries in Caucasian women with varying degrees of glucose tolerance.Research design and methods.  From a population‐based cohort of 64‐year‐old Swedish women, 533 subjects with type 2 diabetes (DM2, n = 177), impaired glucose tolerance (IGT; n = 178) or normal glucose tolerance (NGT, n = 178) were recruited. Anthropometrics, usual cardiovascular risk factors were examined and ultrasound examination of the carotid arteries was performed.Results.  Women with low adiponectin concentrations were characterized by thick IMT, higher prevalence of DM2, history of previous myocardial infarction, angina pectoris, anti‐hypertensive treatment and high body mass index (BMI), waist circumference, plasma insulin, serum triglycerides, fasting glucose, HbA1c, and low serum HDL cholesterol levels. Carotid IMT correlated with HbA1c (r = 0.24, P < 0.001), waist circumference (r = 0.22, P < 0.001), plasma insulin (r = 0.19, P < 0.001), BMI (r = 0.18, P < 0.001), DM2 (r = 0.16, P < 0.001), systolic blood pressure (r = 0.16, P < 0.001), blood glucose (r = 0.16, P < 0.001), triglycerides (r = 0.15, P < 0.001), and reversely to adiponectin (r = −0.11, P = 0.01), HDL cholesterol (r = −0.13, P = 0.004), and alcohol intake (r = −0.087, P < 0.05). A more detailed analysis of underlying associations was difficult due to a high co‐linearity between these variable.Conclusions.  Low serum adiponectin concentrations were associated with increased carotid artery IMT, and several risk factors for cardiovascular diseases, mainly those constituting the metabolic syndrome.
Conservation genetics and the resilience of reef‐building corals
Authors: VAN OPPEN MADELEINE J. H. , GATES RUTH D. 
Published: July 2006

AbstractCoral reefs have suffered long‐term decline due to a range of anthropogenic disturbances and are now also under threat from climate change. For appropriate management of these vulnerable and valuable ecosystems it is important to understand the factors and processes that determine their resilience and that of the organisms inhabiting them, as well as those that have led to existing patterns of coral reef biodiversity. The scleractinian (stony) corals deposit the structural framework that supports and promotes the maintenance of biological diversity and complexity of coral reefs, and as such, are major components of these ecosystems. The success of reef‐building corals is related to their obligate symbiotic association with dinoflagellates of the genus Symbiodinium. These one‐celled algal symbionts (zooxanthellae) live in the endodermal tissues of their coral host, provide most of the host's energy budget and promote rapid calcification. Furthermore, zooxanthellae are the main primary producers on coral reefs due to the oligotrophic nature of the surrounding waters. In this review paper, we summarize and critically evaluate studies that have employed genetics and/or molecular biology in examining questions relating to the evolution and ecology of reef‐building corals and their algal endosymbionts, and that bear relevance to coral reef conservation. We discuss how these studies can focus future efforts, and examine how these approaches enhance our understanding of the resilience of reef‐building corals.
Spatial population genetic structure and limited dispersal in a Rocky Mountain alpine stream insect
Authors: FINN DEBRA S. , THEOBALD DAVID M. , BLACK WILLIAM C. , POFF N. LEROY 
Published: July 2006

AbstractUsing the mitochondrial cytochrome oxidase I (COI) gene, we assessed the phylogeographic structure ofProsimulium neomacropyga, a black fly (Simuliidae) whose distribution in the US Southern Rockies ecoregion is limited to alpine tundra streams. Given high habitat specificity, lack of hydrological connection between streams, and a terrestrial environment restrictive to insect flight, we hypothesized limited gene flow. A spatially nested sampling design showed that grouping populations according to high‐elevation ‘islands’ of alpine tundra (which typically include headwater streams of > 1 watershed) explained a significant proportion of genetic variation while grouping streams according to major watershed (across islands) did not. Nested clade analysis and isolation‐by‐distance (IBD) relationships further implicated limited ongoing gene flow within but not among the isolated alpine islands. IBD was strong among five streams within an individual island using each of four alternative models of pairwise landscape connectivity for flying insects. Results of all landscape models were positively correlated, suggesting that straight‐line distance is an acceptable surrogate for presumably more biologically meaningful connectivity measures in this system. IBD was significantly weaker across the entire study area, comprised of three separate islands. Overall, population structure was significant withFST = 0.38, suggesting limited dispersal across a small spatial extent.
Conservation value of degraded habitats for forest birds in southern Peninsular Malaysia
Authors: Peh Kelvin S.‐H. , Sodhi Navjot S. , De Jong Johnny , Sekercioglu Cagan H. , Yap Charlotte A.‐M. , Lim Susan L.‐H. 
Published: July 2006

ABSTRACTClearance of tropical forest for agricultural purposes is generally assumed to seriously threaten the survival of forest species. In this study, we quantified the conservation value, for forest bird species, of three degraded habitat types in Peninsular Malaysia, namely rubber tree plantations, oil palm plantations, and open areas. We surveyed these degraded habitats using point counts to estimate their forest bird species richness and abundance. We assessed whether richness, abundance, and activities of different avian dietary groups (i.e. insectivores and frugivores) varied among the habitats. We identified the critical habitat elements that accounted for the distribution of forest avifauna in these degraded habitats. Our results showed that these habitats harboured a moderate fraction of forest avifauna (approximately 46–76 species) and their functions were complementary (i.e. rubber tree plantations for moving; open habitats for perching; shrubs in oil palm plantations for foraging). In terms of species richness and abundance, rubber tree plantations were more important than oil palm plantations and open habitats. The relatively high species richness of this agricultural landscape was partly due to the contiguity of our study areas with extensive forest areas. Forecasts of forest‐species presence under various canopy cover scenarios suggest that leaving isolated trees among non‐arboreal crops could greatly attract relatively tolerant species that require tree canopy. The conservation value of degraded habitats in agricultural landscapes seems to depend on factors such as the type of crops planted and distance to primary forest remnants.
Field Cricket Species Differences in the Temporal Patterns of Long‐Distance Mate Attraction Signals
Authors: Bertram Susan M. , Bowen Mia 
Published: July 2006

AbstractWe quantify variation in the temporal components of long‐distance mate attraction signals produced by a North American field cricket, Gryllus rubens Scudder. Total signaling time, trilling bout duration, and hourly bout number exhibit high repeatability within individuals. Extensive variation exists across individuals: some males never signal while others signal for several hours each night; of the signalers, average trilling bout duration ranges from <1 min to well over an hour; some males produce only one trilling bout in an evening while others produce three bouts every 2 h. Body size, weight, wing morphology, and condition do not appear to explain the variation. We compare the temporal signaling components of G. rubens with its sister species, G. texensis. Although G. rubens produce slightly more trills per hour with slightly shorter trilling bout durations, the temporal components of these long‐distance mate attraction signals are surprisingly similar across species.
Age‐Related Changes in Signalling of Need by Nestling Tree Swallows (Tachycineta bicolor)
Authors: Leonard Marty L. , Horn Andrew G. 
Published: July 2006

AbstractDespite a large literature on the ontogeny of behaviour, few studies have examined how the function of juvenile behaviour changes during development. One of the most widespread and important juvenile behaviours is begging, the display used by young animals to solicit food from their parents. Begging signals generally vary reliably with offspring need for food and have served as models for understanding the evolution of honest signalling. Little is known, however, about whether the relationship between begging and need varies over the period of rapid juvenile development. Here, we examine whether tree swallow,Tachycineta bicolor, begging calls consistently reflect hunger levels across the 20 d nestling period. We recorded begging calls at 5, 10 and 15 d post‐hatch, during an hour of food deprivation, and related call features to time without food (i.e. hunger) at each age. The overall correlation between call structure and hunger, as measured by canonical correlation, was consistent across ages. The particular features that correlated with hunger varied, however. Call rate and length increased with hunger at all ages, but call amplitude and frequency range increased with hunger at days 10 and 15 only. The results of our study suggest that begging calls consistently convey information about offspring hunger throughout the nestling period, with the number of call features encoding hunger increasing with nestling age. This change may enhance the ability of parents to assess offspring hunger levels by adding redundancy to the signal.
Social Dominance among Male Meadow Voles is Inversely Related to Reproductive Success
Authors: Spritzer Mark D. , Solomon Nancy G. , Meikle Douglas B. 
Published: July 2006

AbstractIntrasexual selection can occur through direct aggressive interactions between males for access to females. We tested the relationship between social dominance and male reproductive success among meadow voles, Microtus pennsylvanicus. Dominance ranks of wild‐caught males were determined using neutral arena trials, with the winner of two of three trials considered dominant. These males were then released into field enclosures and allowed to visit females housed in nestboxes for 8 wk, and males’ home range sizes were determined using weekly grid trapping. Male reproductive success was determined using molecular paternity analysis (six microsatellite primers) for all pups born during the field experiment. Males with higher dominance ranks had larger home ranges. However, male dominance rank was not predictive of the number of total visits to females’ nestboxes or the number of visits to each male's most frequently visited nestbox. Males that made more visits to nestboxes sired more litters. Males that had higher dominance ranks sired fewer litters. These results suggest that there is a reproductive disadvantage to having higher dominance rank among male meadow voles.
Synthetic Prions
Authors: Eiden M. , Buschmann A. , Kupfer L. , Groschup M. H. 
Published: July 2006

SummaryThe prion theory postulates that prions are novel infectious agents that are composed largely, if not entirely, of abnormally folded host‐encoded prion proteins. However, the existence of different prion strains is enigma, if these novel infectious agents lack a genetic element, such as a nucleic acid. The best proof for this ‘protein‐only’ concept would be the in vitro generation of prions from synthetic sources. Indeed, a substantial body of evidence has meanwhile been accumulated in favour of this postulate. This mini review recapitulates all relevant studies and experimental data on the generation of synthetic prions.
Analysis of common transforming growth factor beta‐1 gene polymorphisms in gastric and duodenal ulcer disease: Pilot study
Authors: Polonikov Alexey V , Ivanov Vladimir P , Belugin Dmitry A , Khoroshaya Irina V , Kolchanova Inessa O , Solodilova Mariya A , Tutochkina Margarita P , Stepchenko Alexander A 
Published: July 2006

AbstractBackground and Aim:  Transforming growth factor‐β1 (TGF‐β1) has been shown to be an important cytokine that plays a role in cell proliferation, differentiation, tissue injury repair and ulcer healing. The purpose of this pilot study was to investigate if common polymorphisms Leu10Pro, Arg25Pro and C‐509T within the TGF‐β1 gene are associated with susceptibility to gastric and duodenal ulcer disease in Russians.Method:  Blood samples from 377 unrelated patients with gastric and duodenal ulcer disease and 226 sex‐ and age‐matched healthy controls were used to determine TGF‐β1 gene polymorphisms by polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP).Results:  Leu10Pro substitution in the signal peptide of TGF‐β1 has been found to be associated with susceptibility to gastric ulcer (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.12–2.77). A genotype combination of 10Leu/Leu × 25Arg/Arg × −509C/C was also associated with susceptibility to gastric ulcer disease (OR 1.81, P = 0.01). In addition, the frequency of a combination of genotypes 10Pro/Pro × 25Arg/Pro × −509C/T was statistically lower in patients with duodenal ulcer than in controls (OR 0.42, P = 0.05). A significant difference (P = 0.04) in the distribution of rare haplotypes of the TGF‐β1 gene between patients with duodenal ulcer and healthy controls has been found. Polymorphism Leu10Pro was in positive linkage disequilibrium with C‐509T polymorphism (coefficient D = 0.191; P < 0.0001).Conclusions:  These findings indicate that the Leu10Pro and C‐509T polymorphisms may be involved in the modulation of expression of the TGF‐β1 gene, and therefore a predisposition to peptic ulcer disease could be linked to particular alleles of this gene. In particular, a possible role of TGF‐β1 in the pathogenesis of gastric ulcer disease is discussed.
Restriction of dietary calories, fat and iron improves non‐alcoholic fatty liver disease
Authors: Yamamoto Mika , Iwasa Motoh , Iwata Kazuko , Kaito Masahiko , Sugimoto Ryosuke , Urawa Naohito , Mifuji Rumi , Konishi Masayoshi , Kobayashi Yoshinao , Adachi Yukihiko 
Published: July 2006

AbstractBackground:  The pathogenesis of non‐alcoholic steatohepatitis (NASH) is unclear. Recent studies suggested that oxidative stress plays an important role in the mechanism of NASH. Excessive accumulation of iron in the liver causes oxidative stress. The aim of the present study was to evaluate the grade of hepatic iron accumulation and the therapeutic response to restriction of calories, fat and iron in patients with non‐alcoholic fatty liver disease (NAFLD).Methods:  Twenty‐seven NAFLD patients were enrolled. The patients were categorized into two groups: 17 patients with NASH and 10 with simple steatosis. Twelve NAFLD patients (NASH, n = 9; simple steatosis, n = 3) were given a dietary prescription including restriction of energy, fat and iron.Results:  Positive iron staining was observed in 71% and 50% of patients with NASH and simple steatosis, respectively. The average energy intake, fat energy fraction and iron intake decreased significantly 6 months after the beginning of the diet in all patients. In addition, the levels of serum transaminase and ferritin were significantly decreased.Conclusion:  Dietary restriction of calories, fat and iron improved NAFLD. Reduced serum ferritin levels appear to reduce oxidative stress in the liver.
Association of body mass index with heartburn, regurgitation and esophagitis: Results of the Progression of Gastroesophageal Reflux Disease study
Authors: Nocon Marc , Labenz Joachim , Jaspersen Daniel , Meyer‐Sabellek Wolfgang , Stolte Manfred , Lind Tore , Malfertheiner Peter , Willich Stefan N 
Published: July 2006

AbstractBackground:  Overweight and obesity are believed to be risk factors for gastroesophageal reflux disease (GERD). The aim of the present study was to analyze the impact of body mass index (BMI) on the severity and frequency of reflux symptoms and esophagitis in a large cohort of reflux patients.Methods:  As part of the Progression of Gastroesophageal Reflux Disease (ProGERD) study, 6215 patients with clinically assessed GERD were included in the present investigation (53% male, 52 ± 14 years; 47% female, 56 ± 14 years). Heartburn and regurgitation symptoms were assessed using the validated Reflux Disease Questionnaire. Endoscopies were performed and patients were subsequently classified as having non‐erosive or erosive disease. To examine the association between BMI, GERD symptoms, and esophagitis, odds ratios (OR) and 95% confidence intervals (95%CI) were calculated using logistic regression models.Results:  In patients with GERD, higher BMI was associated with more frequent and more severe heartburn and regurgitation, as well as with esophagitis. The effects were more pronounced for regurgitation than for heartburn. The strongest association was between obesity and severity of regurgitation symptoms (women: OR 2.11, 95%CI 1.60–2.77; men: OR 2.15, 95%CI 1.59–2.90). Obese women, but not men, had an increased risk of severe esophagitis compared to women with normal weight (OR 2.51, 95%CI 1.53–4.12).Conclusions:  In patients with GERD, higher BMI was associated with more severe and more frequent reflux symptoms and esophagitis.
Transient hyperphosphatasemia after pediatric liver transplantation
Authors: ARIKAN CIGDEM , ARSLAN MEHMET TAYYIP , KILIC MURAT , AYDOGDU SEMA 
Published: July 2006

AbstractBackground: Transient hyperphosphatasemia of infancy and early childhood is characterized by transiently increased serum activity of alkaline phosphatase (ALP), predominantly its bone or liver isoform, in children under 5 years of age. There is little information on the rate of transient hyperphosphatasemia in pediatric liver transplant recipients.Methods: Patients who underwent liver transplantation at Ege University Organ Transplantation and Research Center, Izmir, Tureky, between January 1998 and January 2005, were included in the study. A total of 70 paediatric liver recipients’ medical records were analyzed retrospectively.Results: Transient isolated hyperphosphatasemia was observed in two of 70 patients and the rate of transient hyperphosphatasemia was estimated to be 2.8% in pediatric liver transplant recipient. Diarrheal episode was noted prior to the peak ALP activity in both cases. In one case the causative agent was not found, whereas in the other case Rotavirus was detected in a stool specimen. ALP activity normalized at 4 months and 18 days in the first and second cases, respectively. They continue follow up at the outpatient clinics with stable graft function.Conclusion: It is important to know that very high ALP levels can be seen without underlying significant pathology and the benign nature of the condition to avoid unnecessary investigations.