bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of sand ripples to change in oscillatory flow
Authors: DOUCETTE J. S. , O'DONOGHUE T. 
Published: March 2006

AbstractRipples take time to evolve to a new equilibrium state in response to a change in wave‐generated oscillatory flow. The paper presents results from flow tunnel experiments designed to examine oscillatory flow transient ripple processes under controlled, full‐scale laboratory conditions. The experiments include study of the growth of ripples from flat bed and the evolution of existing ripples to new equilibrium ripples in response to a step change in the flow. In general, ripples evolve through a combination of two main processes: (i) from a flat bed or from a bed consisting of ripples that are smaller than the equilibrium ripples through a combination of ‘slide’ and ‘merge’; (ii) from a bed consisting of ripples that are larger than the equilibrium ripples through a combination of ‘split’ and ‘merge’. The experimental results show that equilibrium ripple geometry is independent of initial bed morphology while the time to reach equilibrium is largely independent of the initial bed and the equilibrium ripple size. The time to reach equilibrium depends strongly on the mobility number, and a new empirical equation relating mobility number and the number of flow cycles to equilibrium is proposed. This equation is combined with a simple exponential function for ripple height growth or decay to produce a new empirical model for ripple height evolution, which gives a reasonably good overall agreement with the measurements. The model is based on experiments involving one sediment size only and further work is needed to develop the model for other sand sizes.
Sediment ingestion by worms and the production of bio‐clays: a study of macrobiologically enhanced weathering and early diagenetic processes
Authors: NEEDHAM S. J. , WORDEN R. H. , CUADROS J. 
Published: March 2006

AbstractThe experiments reported here show that a range of early diagenetic clay minerals can develop within ingested sand in the guts of creatures at a rate that is at least 2 or 3 orders of magnitude greater than in an abiotic environment. Early diagenesis in marine environments may be strongly influenced by the occurrence of sediment ingestion and excretion by animals. Using a set of artificial marine experiments and the common lugworm Arenicola marina, it is shown that sediment ingestion by macrobiota represents a new way in which to precipitate clay minerals or ‘bio‐clays’. Significant quantities of clay minerals can be the product of biological interaction within sediment. Tanks were constructed with artificially layered sediment and natural seawater. The experiments were conducted at room temperature for a total duration of 9 months. The silicate material fed to the worms was an unweathered, and thus clay mineral‐free, basalt from Iceland. Less than 2 μm fractions from original, control and faecal samples were periodically analysed using X‐ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Faecal casts underwent mineral alteration as denoted by loss of primary minerals, especially plagioclase. New minerals in faecal casts from the lugworms included, kaolinite, illite, quartz and possibly chlorite. Inorganic weathering of similar parent basalt would probably produce an identical mineral assemblage but many more times slowly than with the macrobiotic mechanism demonstrated here.
Does saltwater flushing reduce viability of diapausing eggs in ship ballast sediment?
Authors: Bailey Sarah A. , Nandakumar Kanavillil , MacIsaac Hugh J. 
Published: March 2006

ABSTRACTFlushing of ballast tanks with seawater has been proposed to reduce the risk of invasion associated with residual ballast in ‘no ballast on board’ ships. The efficacy of this procedure, however, has not been determined. Using diapausing eggs isolated from ballast sediments — as well as from Lake Erie sediment — this study investigated the impact of salinity (0, 8 and 35‰) and temperature (10, 20 and 30 °C) on the cumulative abundance and species richness of hatched zooplankton taxa. The rate and amount of hatching varied dramatically between sediments and across salinity–temperature regimes. Although exposure to saline water inhibited emergence of freshwater taxa during the exposure phase of all trials, mixed results were evident after diapausing eggs were returned to freshwater. The efficacy of salinity as a ballast treatment method was temperature dependent, although the direction of the effect was case‐specific. Exposure of eggs to saline water was less effective at 10 and 30 °C than at 20 °C. Although flushing ballast tanks with open ocean water is expected to significantly reduce the number of active invertebrates living in residual ballast water (a potentially larger source of invaders), our results indicate that the most effective treatment conditions for reduction of diapausing egg viability is 8‰ salinity at 20 °C.
Systemic stress increases serum leptin level
Authors: Konishi Noriaki , Otaka Michiro , Odashima Masaru , Jin Mario , Wada Isao , Komatsu Koga , Sato Toshihiro , Kato Sayuri , Matsuhashi Tamotsu , Watanabe Sumio 
Published: March 2006

AbstractBackground and Aim:  Leptin, the product of the obese (ob) gene, is a circulating peptide mainly synthesized by adipocytes. Leptin inhibits food intake and decreases body weight. A recent report has suggested that the gastric mucosa is also the source of leptin, and that the stomach leptin also contributes to the regulation of the serum leptin level. The aim of the present study was to investigate the effect of water‐immersion stress on serum, stomach and adipose tissue leptin levels to understand the relationship between stress and eating behavior.Methods:  Male Sprague–Dawley rats were used in this experiment. The leptin level in the serum, gastric mucosa and adipose tissue was measured using ELISA system before and after the initiation of water‐immersion stress.Results:  The serum leptin level was significantly increased by water‐immersion stress. The peak was observed 9 h after the initiation of the stress (P < 0.01). However, the gastric leptin level significantly decreased 6 and 9 h after the stress. The adipose tissue leptin level significantly increased 3 h after the stress.Conclusions:  The results suggest that changes in serum leptin levels could be associated with stimulation of leptin secretion from the gastric mucosa and leptin production in the adipose tissue by systemic stress and that leptin might be regulated by stress‐related events.
Influence of methylated p15 INK4b and p16 INK4a genes on clinicopathological features in colorectal cancer
Authors: Ishiguro Atsushi , Takahata Takenori , Saito Masato , Yoshiya Gen , Tamura Yoshihiro , Sasaki Mutsuo , Munakata Akihiro 
Published: March 2006

AbstractBackground and Aim:  Genetic silencing by promoter methylation has attracted attention in the carcinogenesis of colorectal cancer. Methylation of the p16INK4a gene has been found in primary colorectal cancer. Although the p15INK4b gene displays high homology to the p16INK4a gene in the amino acid sequence, methylation of p15INK4b has not been fully studied. We investigated p15INK4b methylation status in patients with colorectal cancer to verify the association between the methylation of p15INK4b and clinicopathological features compared with p16INK4a.Methods:  DNA samples from the tissues of primary colorectal cancer and corresponding adjacent normal colon mucosa were obtained from surgical resections of 88 patients (47 males and 41 females, aged 29–83 years). Methylation‐specific polymerase chain reaction was used to analyze p15INK4b and p16INK4a methylation status after bisulfite modification. Cumulative survival rates (mean follow‐up period: 53.2 months) were calculated by the Kaplan‐Meier analysis.Results:  Methylations of p15INK4b and p16INK4a genes were detected in 23 (26.1%) and 20 (22.7%) colorectal cancers, respectively. Methylation of p15INK4b was not associated with any clinicopathological features. Compared with normal mucosa, the methylation of p15INK4b was more prominent in tumor tissue (P < 0.001). Reverse transcription‐polymerase chain reaction (RT‐PCR) revealed that p15INK4b methylaton decreased mRNA expression. Kaplan‐Meier analysis showed that patients with stage I‐II had a significant difference in survival rate between those with and without methylated p15INK4b (P = 0.018).Conclusions:  Our results suggest that methylation of the p15INK4b gene contributes to the process of carcinogenesis in colorectal cancer as well as p16INK4a and is useful as a prognostic factor in the early stage.
Circadian change of cardiac autonomic function in correlation with intra‐esophageal pH
Authors: Lee Yi‐Chia , Wang Hsiu‐Po , Lin Lian‐Yu , Chuang Kai‐Jen , Chiu Han‐Mo , Wu Ming‐Shiang , Chen Ming‐Fong , Lin Jaw‐Town 
Published: March 2006

AbstractBackground and Aim:  Although autonomic alterations are observed in patients with gastroesophageal reflux disease (GERD), the influence of visceral receptor responses on the dynamics of autonomic function remains unknown. The aim of this study was to investigate the autonomic functional changes in association with intra‐esophageal pH under ambulation.Methods:  Thirty patients referred for 48 h ambulatory pH monitoring underwent simultaneous 24 h cardiac monitoring for heart rate variability (HRV). We used linear mixed‐effects models to estimate the relationship between esophageal acid exposure and power spectral analysis of HRV, including low‐frequency power (0.04 < LF < 0.15 Hz), high‐frequency power (0.15 < or = HF < 0.4 Hz), and LF/HF power ratio.Results:  Over the 24‐h period, patients with pathological reflux had lower average LF and HF powers than patients with functional heartburn, but the LF/HF power ratios were similar for the two patient groups. As we stratified the data according to waking and sleeping times, a significantly higher HF power but lower LF/HF power ratio was found during sleeping time regardless of diagnosis. In the regression analysis, esophageal pH was positively associated with change (not basal tone) of both LF and HF powers during waking, but only with change of HF power during sleeping time. The significant associations between pH values and changes in HRV decreased gradually with time. The LF/HF power ratio did not alter significantly with pH.Conclusion:  Esophageal acid exposure is generally associated with decreases in autonomic tone. A predominant parasympathetic fluctuation during sleeping and a superimposed sympathetic interaction during waking dictate diurnal characteristics of autonomic regulation.
Prevalence of irritable bowel syndrome in Korea: Population‐based survey using the Rome II criteria
Authors: Han Sung Hee , Lee Oh Young , Bae Sang Cheol , Lee Seok Hwa , Chang Yu Kyung , Yang Sun Young , Yoon Byung Chul , Choi Ho Soon , Hahm Joon Soo , Lee Min Ho , Lee Dong Hoo , Kim Tae Hwa 
Published: March 2006

AbstractBackground:  Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder in the West. But information on the prevalence of IBS in Asia is still lacking, especially in Korea. Therefore, the aims of the present study were to estimate the prevalence of IBS in the general population of Korea and also to investigate characteristics of IBS and health‐care‐seeking behavior of IBS patients.Methods:  Telephone interview survey was conducted by Gallup, Korea using a validated questionnaire based on the Rome II criteria. The response rate of the telephone interview survey was 25.2% (n = 1066, 535 male and 531 female responders). A random sample of gender and age (between 18 and 60 years), based on a per capita ratio was obtained.Results:  Among 1066 subjects, the prevalence of IBS was 6.6% (70 subjects; 7.1%, male; 6.0%, female). The difference in IBS prevalence by gender was not significant. The prevalence was higher among those in their 20s (P = 0.036). Among 70 subjects with IBS, 10/20 IBS subjects sought health care due to abdominal pain. Among the risk factors of IBS, marital status had a significant difference; the following risk factors are arranged in descending order: age (odds ratio [OR]: 1.38, 95% confidence interval [CI]: 0.85–2.25), alcohol intake (OR: 1.38, 95%CI: 0.81–2.35), gender (OR: 1.19, 95%CI: 0.73–1.94), demographics (OR: 1.09, 95%CI: 0.53–2.25), income (OR: 0.88, 95%CI: 0.54–1.45), education level (OR: 0.81, 95%CI: 0.46–1.40), smoking (OR: 0.64, 95%CI: 0.37–1.12), and marital status (OR: 0.59, 95%CI: 0.35–0.99).Conclusions:  The prevalence of IBS in the Korean population is 6.6%, and the male : female ratio is similar. Also, IBS is more frequent in younger subjects. Irritable bowel syndrome subjects visited a physician mostly due to abdominal pain.
Silent myocardial ischemia in coronary artery disease patients under aspirin therapy presenting with upper gastrointestinal hemorrhage
Authors: Chen Chien‐Chih , Chong Chee‐Fah , Kuo Cheng‐Deng , Wang Tzong‐Luen 
Published: March 2006

AbstractAim:  To identify the risk factors for myocardial ischemia in patients undergoing aspirin therapy for coronary artery disease (CAD) presenting with upper gastrointestinal hemorrhage and to ascertain the impacts on mortality and length of hospital stay.Methods:  Adults with CAD under aspirin therapy (100 mg once daily) presenting to the emergency department with upper gastrointestinal hemorrhage were retrospectively recruited and divided into group A (ischemia) and group B (non‐ischemia). Charts were reviewed for various demographic, laboratory and outcome data. Electrocardiograms were interpreted blindly by a senior cardiologist.Results:  A total of 152 patients, 72.4% men and 27.6% women, were analyzed. Of these, 31 patients had ischemia and were placed in group A and 121 patients did not have ischemia and were in group B. Independent multivariate predictors of myocardial ischemia were history of triple vessel disease (odds ratio [OR], 9.24; 95% confidence interval [CI], 2.00–42.72), lower diastolic blood pressure (OR, 1.09; 95% CI, 1.02–1.16), lower hematocrit (OR, 1.41; 95% CI, 1.16–1.70), and higher blood urea nitrogen (OR, 0.94; 95% CI, 0.89–0.98). Patients with myocardial ischemia had significantly longer hospital length of stay (8.7 ± 4.0 days vs 5.4 ± 1.7 days; P < 0.001) and higher in‐hospital mortality (16.1%vs 2.5%; P < 0.01) than did those without myocardial ischemia.Conclusion:  Myocardial ischemia is a relatively common complication in CAD patients under aspirin therapy presenting with upper gastrointestinal hemorrhage. A history of CAD with triple vessel disease, higher blood urea nitrogen, lower diastolic blood pressure and lower hematocrit may help identify patients who are at increased risk of myocardial ischemia, which tends to be associated with higher in‐hospital mortality and increased length of hospital stay.
Influences of Helicobacter pylori on cyclooxygenase‐2 expression and prostaglandinE2 synthesis in rat gastric epithelial cells in vitro
Authors: Shen Hong , Sun Wei‐Hao , Xue Qi‐Ping , Wu Jing , Cheng Yun‐Lin , Ding Guo‐Xian , Fu Hai‐Ying , Tsuji Shingo , Kawano Sunao 
Published: March 2006

AbstractBackground and Aim:  It is known that cyclooxygenase (COX)‐2 is over expressed in gastrointestinal neoplasia and Helicobacter pylori (H. pylori) infection is causally linked to gastric cancer. The present study aimed to elucidate the effects of H. pylori on COX‐2 expression and prostaglandinE2 (PGE2) production in a gastric epithelial cell line derived from normal rat gastric mucosa (RGM1).Method:  H. pylori water extracts were prepared from a supernatant of the H. pylori suspension in distilled water. RGM1 cells were cultured with H. pylori water extracts at the final concentration of 2.5, 5, 10 µg/mL for 24 h. For the time sequence study, RGM1 cells were cultured with 10 µg/mL H. pylori water extracts for 0, 6, 12, 24 and 48 h. COX‐1 and COX‐2 expression in the RGM1 cells was analyzed by western blotting. The levels of PGE2 in the cultured media were measured by enzyme immunoassay.Results:  H. pylori did not affect COX‐1 expression; whereas COX‐2 expression increased by six‐fold at 24 h after incubation of RGM1 cells with 10 µg/mL H. pylori water extracts. The increase in COX‐2 expression was evident after 12 h of incubation; reached a peak at 24 h and declined at 48 h. H. pylori dose dependently increased COX‐2 expression and PGE2 synthesis in RGM1 cells.Conclusion:  H. pylori induces COX‐2 expression and increases PGE2 synthesis in RGM1 cells in vitro. These results indicate that H. pylori‐associated gastric carcinogenesis may depend on COX‐2 expression.
Constipation of anorectal outlet obstruction: Pathophysiology, evaluation and management
Authors: Andromanakos Nikolaos , Skandalakis Panayiotis , Troupis Theodoros , Filippou Dimitrios 
Published: March 2006

AbstractConstipation is a subjective symptom of various pathological conditions. Incidence of constipation fluctuates from 2 to 30% in the general population. Approximately 50% of constipated patients referred to tertiary care centers have obstructed defecation constipation. Constipation of obstructed defecation may be due to mechanical causes or functional disorders of the anorectal region. Mechanical causes are related to morphological abnormalities of the anorectum (megarectum, rectal prolapse, rectocele, enterocele, neoplasms, stenosis). Functional disorders are associated with neurological disorders and dysfunction of the pelvic floor muscles or anorectal muscles (anismus, descending perineum syndrome, Hirschsprung's disease). However, this type of constipation should be differentiated by colonic slow transit constipation which, if coexists, should be managed to a second time. Assessment of patients with severe constipation includes a good history, physical examination and specialized investigations (colonic transit time, anorectal manometry, rectal balloon expulsion test, defecography, electromyography), which contribute to the diagnosis and the differential diagnosis of the cause of the obstructed defecation. Thereby, constipated patients can be given appropriate treatment for their problem, which may be conservative (bulk agents, high‐fiber diet or laxatives), biofeedback training or surgery.
Nicotine exposure in vivo induces long‐lasting enhancement of NMDA receptor‐mediated currents in the hippocampus
Authors: Yamazaki Yoshihiko , Jia Yousheng , Niu Rong , Sumikawa Katumi 
Published: March 2006

AbstractThe use of nicotine via cigarette smoking forms long‐lasting memories that are recalled in response to environmental cues associated with previous nicotine use. However, the changes in brain memory systems that underlie these long‐lasting memories are not well understood. The N‐methyl‐d‐aspartate receptor (NMDAR) is critical for long‐lasting modifications of synapses. Here we show that in vivo nicotine exposure induces the enhancement of NR2B‐containing NMDAR‐mediated currents in the hippocampus, a brain region associated with the formation of memories. This nicotine effect is maintained during continued nicotine exposure and is accompanied by increased tyrosine phosphorylation of NR2B. Furthermore, long‐term potentiation (LTP), which is considered to be a cellular substrate of learning and memory, induced in nicotine‐exposed hippocampi contains a protein synthesis‐independent long‐lasting component. An NR2B‐selective antagonist blocks a long‐lasting component of LTP, but not LTP. These results suggest that exposure to nicotine provides conditions that promote the induction of long‐lasting modifications of synapses, which may be involved in the formation of memories involving nicotine use.
Spillover edge effects: the dispersal of agriculturally subsidized insect natural enemies into adjacent natural habitats
Authors: Rand Tatyana A. , Tylianakis Jason M. , Tscharntke Teja 
Published: March 2006

AbstractThe cross‐edge spillover of subsidized predators from anthropogenic to natural habitats is an important process affecting wildlife, especially bird, populations in fragmented landscapes. However, the importance of the spillover of insect natural enemies from agricultural to natural habitats is unknown, despite the abundance of studies examining movement in the opposite direction. Here, we synthesize studies from various ecological sub‐disciplines to suggest that spillover of agriculturally subsidized insect natural enemies may be an important process affecting prey populations in natural habitat fragments. This contention is based on (1) the ubiquity of agricultural–natural edges in human dominated landscapes; (2) the substantial literature illustrating that crop and natural habitats share important insect predators; and (3) the clear importance of the landscape matrix, specifically distance to ecological edges, in influencing predator impacts in agroecosystems. Further support emerges from theory on the importance of cross‐boundary subsidies for within site consumer–resource dynamics. In particular, high productivity and temporally variable resource abundance in agricultural systems are predicted to result in strong spillover effects. More empirical work examining the prevalence and significance of such natural enemy spillover will be critical to a broader understanding of fragmentation impacts on insect predator–prey interactions.
DISTRIBUTION‐INVARIANT RISK MEASURES, INFORMATION, AND DYNAMIC CONSISTENCY
Authors: Weber Stefan 
Published: March 2006

In the first part of the paper, we characterize distribution‐invariant risk measures with convex acceptance and rejection sets on the level of distributions. It is shown that these risk measures are closely related to utility‐based shortfall risk.In the second part of the paper, we provide an axiomatic characterization for distribution‐invariant dynamic risk measures of terminal payments. We prove a representation theorem and investigate the relation to static risk measures. A key insight of the paper is that dynamic consistency and the notion of “measure convex sets of probability measures” are intimately related. This result implies that under weak conditions dynamically consistent dynamic risk measures can be represented by static utility‐based shortfall risk.
Dealing with Uncertainty: Managing Personal Investment in the Early English National Debt
Authors: MURPHY ANNE L. 
Published: March 2006

AbstractDuring the late seventeenth century there was a ‘Financial Revolution’ in England. Prompted by the exigencies of the Nine Years War (1689–97), the state marked the beginnings of a permanently funded National Debt by introducing a series of measures, the most important of which was the foundation of the Bank of England in 1694. The state's financial innovations were enthusiastically supported by London's business community and also attracted the capital and the trust of investors of more limited means and financial knowledge. Through the surviving papers of Samuel Jeake, a merchant from the East Sussex town of Rye, this article considers the strategies used by those less prominent investors, and examines the methods they used to obtain financial information and the costs they faced. Jeake's experiences reveal much about the factors that led ordinary investors to commit their capital to the newly established public funds but show that, during the formative period of the Financial Revolution, the costs of placing faith in the state's financial promises often outweighed the benefits.