bluuebunny/crossref_metadata_2025_split huggingface dataset:
The geological methane budget at Continental Margins and its influence on climate change
Authors: Judd A. G. , Hovland M. , Dimitrov L. I. , García Gil S. , Jukes V. 
Published: March 2003

AbstractGeological methane, generated by microbial decay and the thermogenic breakdown of organic matter, migrates towards the surface (seabed) to be trapped in reservoirs, sequestered by gas hydrates or escape through natural gas seeps or mud volcanoes (via ebullition). The total annual geological contribution to the atmosphere is estimated as 16–40 Terragrammes (Tg) methane; much of this natural flux is ‘fossil’ in origin. Emissions are affected by surface conditions (particularly the extent of ice sheets and permafrost), eustatic sea‐level and ocean bottom‐water temperatures. However, the different reservoirs and pathways are affected in different ways. Consequently, geological sources provide both positive and negative feedback to global warming and global cooling. Gas hydrates are not the only geological contributors to feedback. It is suggested that, together, these geological sources and reservoirs influence the direction and speed of global climate change, and constrain the extremes of climate.
The use and abuse of frying oil
Authors: McSavage J. , Trevisan S. 
Published: March 2003

AbstractThe quality of frying oil discarded by a sample of catering establishments was assessed using a rapid test method, which measures the free fatty acid (FFA) concentration. Results show that none of the establishments used an objective assessment method; a lack of consistency between establishments, and many discarding oil where the FFA levels were above the recommended safe level. Analysis of used oil samples demonstrated, that the use of subjective methods lead, in the majority of cases, either to the abuse or underuse of the frying agent. The use of a simple, convenient‐to‐use, objective measurement is recommended.
Current environmental issues: a study of Sinai and Red Sea hotels
Authors: Kattara H. S. , Zeid A. W. 
Published: March 2003

AbstractEnvironmental issues are now a concern in many industries including the food service and hospitality industries. This paper examines environmental issues in hotels in the newly developed tourist areas of the Sinai and Red Sea. Various environmental issues were studied including environmental practices, managers attitudes towards environmental issues, future environmental practices and anticipated hotel profitability resulting from applying environmental practices. Results show an opportunity to promote environmental practices in hotels and a high level of awareness and willingness of managers to preserve the environment.
Invasibility and diversity of plant communities:from patterns to processes
Authors: Lavorel S. , Prieur‐Richard A.‐H. , Grigulis K. 
Published: March 2003

SummaryResearch on the function of biodiversity has stimulated a renewed interest in the mechanisms underlying the invasibility of plant communities. Conflicting results provide evidence that observational correlative studies are a dead end if isolated from manipulative experiments. Using two studies in France, Portugal and Australia we illustrate how invasion research can move from pattern observation to the investigation of processes.Artificial annual communities representing a factorial combination of one to three functional groups and one to six species per group were sown in Montpellier. Natural invasibility of the plots from the seed bank showed no strong relationship with functional or species richness. The survival of individuals of two congeneric exotic species (Conyza canadensis and C. bonariensis) introduced as seedlings did not relate to these simple diversity indices. On the other hand, their adult biomass did with a decrease in vegetative performance with increasing species richness but a decrease with increasing number of functional groups. Survival and biomass of invaders were strongly influenced by the identity of the resident functional groups.In a study of the mechanisms underlying the demographic success of the pasture weed Echium plantagineum in Australia, germinations in mixtures with varying numbers, densities, and identities of co‐germinants showed no evidence that increasing diversity increased the competitive effect. Rather, significant reduction of recruitment resulted from increased densities.These examples suggest that patterns and mechan‐ isms of community invasibility are likely to be far more subtle than people have acknowledged so far. Controlled experiments coupled with theoretical work are required to advance our understanding.
Alpha diversity of lianas in a tropical evergreen forest in the Anamalais, Western Ghats, India
Authors: Muthuramkumar S. , Parthasarathy N. 
Published: March 2003

Abstract. Species richness, abundance, size‐class distribution, climbing mode and spatial patterns of lianas were investigated in a 30‐ha permanent plot of tropical evergreen forest at Varagalaiar in the Anamalais, Western Ghats, India. Each hectare was subdivided into 10 m × 10 m quadrats, in which all lianas ≥ 1 cm d.b.h. were measured, tagged and identified. The total liana density was 11, 200 individuals (373 ha–1) and species richness was 75 species, representing 66 genera and 37 families. The richness estimators employed for species and family accumulation curves after 100 times randomization of sample order, have stabilized the curves at 16th and 15th hectares, respectively. A greater proportion of lianas was twiners (55% of species and 44.4% of density) and root climbers (5% of species and 14% of density), and a few were tendril climbers, reflecting the late successional stage of the forest. In the size‐class distribution, 82% of abundance and 97% of species richness fell within 1–3 cm diameter threshold. The dominance of succulent diaspore type signifies the faunal dependence of lianas on vertebrate frugivores for dispersal. The diversity, population density and family composition of lianas of our site is compared with those of other tropical forests. The need for biomonitoring of this synusia in the permanent plot for forest functioning is emphasized.
Exposure of rat isolated stomach and rats in vivo to [14C]agmatine: accumulation in the stomach wall and distribution in various tissues
Authors: Molderings Gerhard J. , Heinen Anja , Menzel Sigrid , Göthert Manfred 
Published: March 2003

The aims of the present study were: (i) to investigate the accumulation of radioactivity in the stomach wall after luminal exposure of the rat isolated stomach to[14C]agmatine and (ii) to determine the distribution of radioactivity in various tissues after oral administration of this radiolabelled polyamine to rats in vivo. In isolated rat stomach, [14C]agmatine was accumulated in part by an energy‐dependent uptake process that could be inhibited by phentolamine. These findings correspond to properties of the recently identified specific agmatine transporter in human glioma cells, suggesting that in rat stomach [14C]agmatine is taken up by such a carrier.In in vivo experiments, rats received 0.5 μCi [14C]agmatine adsorbed to 5 g rat standard chow after a fasting period of 24 h. After oral ingestion of [14C]agmatine, radioactivity was recovered in all organs investigated as well as in blood and urine. Radioactivity also seemed to be secreted into the pancreaticobiliary fluid, as it was recovered in the luminal content of distal ileum and sigmoid colon. Accumulation of radioactivity in organs and distal gut luminal content was dose‐dependently decreased by simultaneous administration of putrescine.In conclusion, the present data are compatible with the view that agmatine can be absorbed in rat at least from the stomach and probably also from the gut by means of an energy‐dependent agmatine transport mechanism. Agmatine itself and/or its degradation products, which also have the potential to be pharmacologically active, are unevenly distributed between the organs. Putative secretion of radioactivity into the pancreaticobiliary fluid suggests the potential for an enterohepatic circulation of agmatine. In view of the high intraluminal concentration of agmatine in the stomach and distal gut and the operation of an agmatine transporter, it is rather likely that agmatine in the chyme of the gut represents an important source for agmatine detected in the tissues of the organism.
Safety pharmacology in the nonclinical assessment of new medicinal products: definition, place, interest and difficulties
Authors: Claude Jean‐Roger 
Published: March 2003

Until the year 2000 there was no internationally‐accepted definition for the terms used in nonclinical pharmacology (primary, secondary pharmacodynamics, discovery, safety pharmacology, etc). Now, after ICH5 (San Diego, November 2000), a harmonisation of the nomenclature is adopted: safety pharmacology is defined as the studies that investigate the potential undesirable pharmacodynamic effects of a medicinal product on physiological functions in relationship to exposure. Consequently, safety pharmacology studies are a part of the safety assessment for a new product, in the same way than toxicological studies, and a basic battery of tests (core battery) has to be conducted prior to the first administration to humans.Safety pharmacology studies are of peculiar interest: they show a good predictive potential for humans, they do not require a large number of laboratory animals, long‐term studies, large amount of products and they are more dynamic and more flexible than toxicological studies. Nevertheless, many difficulties occur for the implementation in industry, related to practical and/or scientific problems: location of the studies, routine activity for the pharmacologists, sometimes difficulties in the relationship between toxicologists and pharmacologists, adaptation to the GLP requirements, elaboration of an early relevant scientific programme, necessity to go to contract‐labs or to academic research for unusual or for up to date methods, etc.To conclude, a retrospective timetable of the regulatory evolution for the last 10 years will be provided, as an illustration of the worldwide progress in the concept of `harmonisation' for the assessment of new medicinal products.
Relationship between exposure to zidovudine and decrease of P24 antigenemia in HIV‐infected patients in monotherapy
Authors: Sasomsin Patrinee , Mentré France , Diquet Bertrand , Simon François , Brun‐Vezinet Françoise 
Published: March 2003

AbstractThe link between virological response and exposure to zidovudine was studied in 40 HIV‐infected patients of the protocol ANRS 01. During this 45‐day trial, the patients received only oral zidovudine in six treatment groups. Our objectives were: to analyze and model the pharmacokinetics of zidovudine and the decrease of P24 antigenemia; to study the links between exposure and efficacy. For the pharmacokinetic study, 12 blood samples were collected from 0.16 to 24 h after the first dose and a compartmental model was used. For the pharmacodynamic study of P24 antigenemia, blood samples were collected before treatment and every 3 days until day 45; an exponantial decay model was used. The pharmacokinetic and pharmacodynamic parameters were estimated for each patient by nonlinear regression. The correlations between efficacy parameters and exposure parameters, were then studied in the 40 patients. The mean (± SD) apparent volume of distribution and clearance were 151 L (± 94) and 184 L/h (± 72), respectively. The mean initial antigen level was 472 pg/mL (± 409), the coefficient of reduction of antigenemia was 0.27 (± 0.21) and the rate of decrease was 0.27/day (± 0.16). The coefficient of P24 reduction was found to be significantly correlated to the daily area under the curve (P < 0.0014). This relationship was adequately described by an Imax model and the daily area under the curve, leading to 50% of antigenemia decrease, was estimated to be 2.32 mg.h/L (± 0.33). In conclusion, a significant relationship between exposure to zidovudine at day 1, and decrease of P24 antigenemia was found. It was estimated that the average steady‐state concentration, which corresponds to 70% of maximal efficacy, was 0.22 mg/L. Together with the large interpatient variability of zidovudine pharmacokinetics, these findings confirmed that zidovudine should be monitored and a clinical target concentration was defined.
Neural networks – a diagnostic tool in acute myocardial infarction with concomitant left bundle branch block
Authors: Olsson Sven‐Erik , Ohlsson Mattias , Öhlin Hans , Edenbrandt Lars 
Published: March 2003

SummaryThe prognosis of acute myocardial infarction (AMI) improves by early revascularization. However the presence of left bundle branch block (LBBB) in the electrocardiogram (ECG) increases the difficulty in recognizing an AMI and different ECG criteria for the diagnosis of AMI have proved to be of limited value. The purpose of this study was to detect AMI in ECGs with LBBB using artificial neural networks and to compare the performance of the networks to that of six sets of conventional ECG criteria and two experienced cardiologists. A total of 518 ECGs, recorded at an emergency department, with a QRS duration >120 ms and an LBBB configuration, were selected from the clinical ECG database. Of this sample 120 ECGs were recorded on patients with AMI, the remaining 398 ECGs being used as a control group. Artificial neural networks of feed‐forward type were trained to classify the ECGs as AMI or not AMI. The neural network showed higher sensitivities than both the cardiologists and the criteria when compared at the same levels of specificity. The sensitivity of the neural network was 12% (P = 0·02) and 19% (P = 0·001) higher than that of the cardiologists. Artificial neural networks can be trained to detect AMI in ECGs with concomitant LBBB more effectively than conventional ECG criteria or experienced cardiologists.
Soft Versus Rigid Vacuum Extractor Cups for Assisted Vaginal Delivery
Authors: Johanson R.B. , Menon B.K.V. 
Published: March 2003

A substantive amendment to this systematic review was last made on 22 June 1999. Cochrane reviews are regularly checked and updated if necessary.ABSTRACT Background and objectives: The original cups used for vacuum extraction delivery of the fetus were rigid metal cups. Subsequently, soft cups of flexible materials such as silicone rubber or plastic were introduced. Soft cups are thought to have a poorer success rate than metal cups. However, they may be less likely to be associated with scalp trauma, easier to apply and less likely to injure the mother. The objective of this review was to assess the effects of soft versus rigid vacuum extractor cups on perineal injury, fetal scalp injury, short and long term pain and success rate. Search strategy: We searched the Cochrane Pregnancy and Childbirth Group trials register. Selection criteria: Acceptably controlled comparisons of soft versus rigid vacuum extractor cups. Data collection and analysis: Two reviewers assessed trial quality and extracted data. Study authors were contacted for additional information. Main results: Nine trials involving 1375 women were included. The trials were of average quality. Soft cups are significantly more likely to fail to achieve vaginal delivery (odds ratio 1.65, 95% confidence interval 1.19–2.29). However, they were associated with less scalp injury (odds ratio 0.45, 95% confidence interval 0.15–0.60). There was no difference between the two groups in terms of maternal injury. Reviewers' conclusions: Metal cups appear to be more suitable for “occipito‐posterior,” transverse and difficult “occipito‐anterior” position deliveries. The soft cups seem to be appropriate for straightforward deliveries. Citation: Johanson RB, Menon BKV. Soft versus rigid vacuum extractor cups for assisted vaginal delivery (Cochrane Review). In: The Cochrane Library, Issue 4, 1999. Oxford: Update Software.••• The preceding reports are abstracts of regularly updated, systematic reviews prepared and maintained by the Cochrane Collaboration. The full texts of the reviews are available in The Cochrane Library (ISSN 1464–780X). See http://www.update‐software.com/cochrane.htm, or contact Update Software,info@update.co.uk, for information on subscribing to The Cochrane Library in your area.Update Software Ltd., Summertown Pavilion, Middle Way, Oxford OX2 7LG, United Kingdom (Tel.: + 44 1865 513902; Fax: + 44 1865 516918).
Soft Versus Rigid Vacuum Extractor Cups for Assisted Vaginal Delivery
Authors: Johanson R.B. , Menon B.K.V. 
Published: March 2003

A substantive amendment to this systematic review was last made on 31 December 1998.ABSTRACT Background and objectives: Proponents of vacuum delivery argue that it should be chosen first for assisted vaginal delivery, because it is less likely to injure the mother. The objective of this review was to assess the effects of vacuum extraction compared to forceps, on failure to achieve delivery and maternal and neonatal morbidity. Search strategy: We searched the Cochrane Pregnancy and Childbirth Group trials register. Selection criteria: Acceptably controlled comparisons of vacuum extraction and forceps delivery. Data collection and analysis: Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Main results: Ten trials were included. The trials were of reasonable quality. Use of the vacuum extractor for assisted vaginal delivery when compared to forceps delivery was associated with significantly less maternal trauma (odds ratio 0.41, 95% confidence interval 0.33–0.50) and with less general and regional anaesthesia. There were more deliveries with vacuum extraction (odds ratio 1.69, 95% confidence interval 1.31–2.19). Fewer caesarean sections were carried out in the vacuum extractor group. However, the vacuum extractor was associated with an increase in neonatal cephalhaematomata and retinal haemorrhages. Serious neonatal injury was uncommon with either instrument. Reviewers' conclusions: Use of the vacuum extractor rather than forceps for assisted delivery appears to reduce maternal morbidity. The reduction in cephalhaematoma and retinal haemorrhages seen with forceps may be a compensatory benefit. Citation: Johanson RB, Menon BKV. Vacuum extraction versus forceps for assisted vaginal delivery (Cochrane Review). In: The Cochrane Library, Issue 2, 1999. Oxford: Update Software.
Helicobacter pylori Colonization Density and Gastric Acid Output in Non‐ulcer Dyspepsia and Duodenal Ulcer Disease
Authors: Mullins Paul D. , Steer Howard W. 
Published: March 2003

Background.The pattern of intragastric Helicobacter pylori colonization and its density may be determined by parietal cell function. H. pylori bacterial products can inhibit gastric acid secretion from the parietal cell. The aim of this investigation was to study the relationship between acid output and intragastric H. pylori distribution and colonization density in duodenal ulcer (DU) and non‐ulcer subjects. The study included 14 patients with active DU, 10 with inactive DU and 10 non‐ulcer dyspeptics.Methods.Acid output studies in response to fasting and maximal pentagastrin stimulation, basal (BAO) and peak (PAO) acid outputs were calculated. A quantitative assessment of H. pylori colonization density in biopsies from five sites of the gastroduodenum in the active ulcer group, and from the antrum in inactive duodenal ulcer and non‐ulcer groups.Results.There were negative correlations between total gastroduodenal bacterial colonization density and, PAO (r− 0.87, p = 0.0025) and BAO (r− 0.635, p < 0.02) in the active ulcer group. There were negative correlations between antral H. pylori colonization density and PAO in the active duodenal ulcer (r− 0.7449, p < 0.01) and non‐ulcer (r− 0.5837, p < 0.1) groups but not in the inactive duodenal ulcer group (r− 0.1869, p > 0.2).Conclusions.An equilibrium is reached between gastroduodenal H. pylori colonization density and gastric acid secretory capacity in active duodenal ulcer disease. It is hypothesized that thresholds of bacterial load and acid secretory capacity, in combination, are required for active ulceration in DU disease.
Efficacy of Lansoprazole in Eradicating Helicobacter pylori: A Meta‐Analysis
Authors: Bazzoli Franco , Pozzato Paolo , Zagari Maurizio , Fossi Stefania , Ricciardiello Luigi , Nicolini Gianni , Berretti Debora , De Luca Luca 
Published: March 2003

Background.The combination of lansoprazole with antibiotics either as double or triple therapy has demonstrated an H. pylori eradication rate of between 80 and 90%. With the aim of providing a complete revision of the results of these clinical studies and a quantification of the efficacy of lansoprazole in eradicating H. pylori and healing peptic ulcers, we have undertaken a meta‐analysis of all the controlled studies published in the literature.Methods.This meta‐analysis reviewed all randomized, controlled clinical trials published as full text articles in English between 1993 and 1996 that reported the efficacy of lansoprazole treatment as monotherapy or in combination with antibiotics in the treatment of peptic ulcer and in eradicating H. pylori. Articles were identified from the literature, which included both manual and computerized research (MEDLINE) and references provided by articles in this area. In order to compare the efficacy of triple therapy comprising lansoprazole vs. another PPI, data from abstracts (n = 5) were used, as no full text articles were located.Results.This systematic review of the literature documents that lansoprazole has a high degree of efficacy in eradicating H. pylori, above all when used within treatment schemes including amoxicillin or clarithromycin, and metronidazole or tinidazole. This efficacy is comparable to that of other PPIs.Conclusions.Triple therapy allows the eradication of H. pylori in more than 85% of cases in patients with peptic ulcer. In addition, there is a substantial comparability of the efficacy of lansoprazole and omeprazole when they are used together with other anti‐infective agents. Thus, lansoprazole appears to offer an option in the eradication of H. pylori.
Helicobacter pylori and Peptic Ulcer Disease Therapies: A Survey of Gastroenterologists in Israel
Authors: Fireman Zvi , Segal Aryeh , Moshkowitz Menachem , Kopelman Yael , Sternberg Amos 
Published: March 2003

Background. Eradication of Helicobacter pylori has become a therapeutic option in the treatment of patients with peptic ulcer disease. The aim of this study was to evaluate the current management strategies of Israeli gastroenterologists in the diagnosis and treatment of H. pylori‐related peptic ulcer disease, 14 years after the discovery of H. pylori. Materials and Methods. A questionnaire was mailed to all specialists in gastroenterology, members of the Israel Gastroenterological Association (IGA). Replies were received from 60% of Israel Board‐certified gastroenterology specialists. Results. Over 89% of the gastroenterologists (89.1%) noted that they recommend anti‐H. pylori treatment. 94.5% said that they treat duodenal ulcer in the first presentation with anti‐H. pylori medication and 75% said that they do so in cases of recurrent duodenal ulcer. According to the replies received, there is a strong consensus towards triple treatment as the favored anti‐H. pylori treatment; no one noted the use of dual treatment. Seven‐day triple treatment was prescribed by 83.6% of the gastroenterologists who responded. Of these, the great majority, 89.1%, stated that they use proton pump inhibitors (PPI) in combination with any two of the following antibiotics: metronidazole (47.3%), tinidazole (29.1%), clarithromycin (61.8%), and amoxicillin (40%). Conclusion. At the time of the survey, most Israel Board‐certified gastroenterology specialists prescribed triple anti‐H. pylori treatment of one‐week’s duration.