bluuebunny/crossref_metadata_2025_split huggingface dataset:
CCK‐1 receptor blockade for treatment of biliary colic: a pilot study
Authors: Malesci A. , Pezzilli R. , D'Amato M. , Rovati L. 
Published: August 2003

SummaryBackground: Loxiglumide is a potent and selective cholecystokinin‐1 (CCK‐1) receptor antagonist able to inhibit gall‐bladder contraction.Aim: To assess the effect of CCK‐1 receptor blockade on the pain of patients with biliary colic.Patients and methods: Fourteen patients with biliary colic but no suspicion for acute cholecystitis, were randomly and blindly assigned to loxiglumide (50 mg i.v.) or hyoscine‐N‐butyl bromide (20 mg i.v.) treatment. Pain intensity was monitored by a Visual Analogue Scale. Patients with less than 80% response at 30 min, were retreated with a second injection of the same compound.Results: Reduction in pain score (mean ± S.E.M.) was faster and significantly greater in patients treated with loxiglumide (n = 7) than in controls (n = 7): 88 ± 7% vs. 47 ± 12% after 20 min, P < 0.05; 92 ± 6% vs. 49 ± 13%, after 30 min, P < 0.05. Only one of seven patients treated with loxiglumide needed a second injection at 30 min (vs. six of seven controls, P < 0.05). No adverse effect was observed after either treatment.Conclusions: Loxiglumide is highly effective in obtaining pain relief in patients with biliary colic. The analgesic effect of CCK‐1 receptor blockade is superior to that of a conventional anticholinergic treatment.
Out of our reach? Assessing the impact of introducing a critical care outreach service
Authors: Pittard A. J. 
Published: August 2003

SummaryAn outreach service was introduced in three surgical wards and the surgical high dependency unit in a large teaching hospital. A modified early warning score and callout algorithm were used to facilitate referrals to the team. Changes in unplanned admission rate to intensive care, length of stay, mortality rate and number of re‐admissions following the introduction of outreach were sought. Following the introduction of the outreach service the emergency admission rate to intensive care fell from 58% to 43% (p = 0.05). These emergency patients had shorter lengths of stay (4.8 days vs. 7.4 days) and had a lower mortality (28.6% vs. 23.5%, p = 0.05). The re‐admission rate also fell from 5.1% to 3.3% (p = 0.05). The outreach service had a significant impact on critical care utilisation.
Survey of abuse and violence by patients and relatives towards intensive care staff
Authors: Lynch J. , Appelboam R. , McQuillan P. J. 
Published: August 2003

SummaryA postal survey of senior nurses in intensive care units in England and Wales was conducted. The aim was to ascertain the frequency of abusive and violent behaviour by patients and relatives towards intensive care staff, discover the perceived causes, effects and documentation of such behaviour and define the current and proposed security arrangements for intensive care units. Response rate was 94%. During the study period, verbal abuse of nurses by patients and by relatives occurred in 87% and 74% of intensive care units, respectively. The relevant figures for doctors were 65% and 59%, respectively. Nurses experienced physical abuse by patients and by relatives in at least 77% and 17% of intensive care units, respectively (doctors 38% and 8%). Illness was the main perceived cause of offences by patients whereas ‘distress’ (45%), alcohol (24%), sociopathic behaviour (27%) were the main putative causes amongst relatives. Whilst 43% of intensive care units have no security system at the door, staff awareness, training and communication skills may be the principle tools in reducing the frequency and consequences of violent and abusive behaviour. This survey probably underestimates the problem.
The effects of concurrent atorvastatin therapy on the pharmacokinetics of intravenous midazolam
Authors: Mc Donnell C. G. , Harte S. , O'Driscoll J. , O'Loughlin C. , Van Pelt F. D. , Shorten G. D. 
Published: August 2003

SummaryMidazolam is a commonly used anaesthetic agent and is metabolised by the 3A4 isoform of the cytochrome P450 enzyme system. Atorvastatin is also metabolised by cytochrome P450 3A4 and, in vitro, atorvastatin inhibits the cytochrome P450 3A4‐mediated metabolism of mexazolam. We hypothesised that concurrent administration of atorvastatin and midazolam would result in altered midazolam pharmacokinetics. Fourteen patients scheduled to undergo general anaesthesia for elective surgery were recruited in a matched pair design to receive intravenous midazolam (0.15 mg.kg−1). Of these patients, seven were taking long‐term atorvastatin. Atorvastatin patients demonstrated a greater area under the curve (889.4 (standard deviation 388.6) ng‐h.ml−1) vs. control patients (629.1 (standard deviation 197.2) ng‐h.ml−1) (p < 0.05). Patients taking atorvastatin also demonstrated a decreased clearance (0.18 (standard deviation 0.08) l‐kg. h−1) vs. control patients (0.27 (standard deviation 0.08) l‐kg.h−1) (p < 0.05). This study suggests that chronically administered atorvastatin decreases the clearance of intravenously administered midazolam.
The contribution of bryophytes to the carbon exchange for a temperate rainforest
Authors: DeLucia Evan H. , Turnbull Matthew H. , Walcroft Adrian S. , Griffin Kevin L. , Tissue David T. , Glenny David , McSeveny Tony M. , Whitehead David 
Published: July 2003

AbstractBryophytes blanket the floor of temperate rainforests in New Zealand and may influence a number of important ecosystem processes, including carbon cycling. Their contribution to forest floor carbon exchange was determined in a mature, undisturbed podocarp‐broadleaved forest in New Zealand, dominated by 100–400‐year‐old rimu (Dacrydium cupressimum) trees. Eight species of mosses and 13 species of liverworts contributed to the 62% cover of the diverse forest floor community. The bryophyte community developed a relatively thin (depth <30 mm), but dense, canopy that experienced elevated CO2 partial pressures (median 46.6 Pa immediately below the bryophyte canopy) relative to the surrounding air (median 37.6 Pa at 100 mm above the canopy). Light‐saturated rates of net CO2 exchange from 14 microcosms collected from the forest floor were highly variable; the maximum rate of net uptake (bryophyte photosynthesis – whole‐plant respiration) per unit ground area at saturating irradiance was 1.9 μmol m−2 s−1 and in one microcosm, the net rate of CO2 exchange was negative (respiration). CO2 exchange for all microcosms was strongly dependent on water content. The average water content in the microcosms ranged from 1375% when fully saturated to 250% when air‐dried. Reduction in water content across this range resulted in an average decrease of 85% in net CO2 uptake per unit ground area.The results from the microcosms were used in a model to estimate annual carbon exchange for the forest floor. This model incorporated hourly variability in average irradiance reaching the forest floor, water content of the bryophyte layer, and air and soil temperature. The annual net carbon uptake by forest floor bryophytes was 103 g m−2, compared to annual carbon efflux from the forest floor (bryophyte and soil respiration) of −1010 g m−2. To put this in perspective of the magnitude of the components of CO2 exchange for the forest floor, the bryophyte layer reclaimed an amount of CO2 equivalent to only about 10% of forest floor respiration (bryophyte plus soil) or ∼11% of soil respiration. The contribution of forest floor bryophytes to productivity in this temperate rainforest was much smaller than in boreal forests, possibly because of differences in species composition and environmental limitations to photosynthesis. Because of their close dependence on water table depth, the contribution of the bryophyte community to ecosystem CO2 exchange may be highly responsive to rapid changes in climate.
Carbon stock changes and carbon sequestration potential of Flemish cropland soils
Authors: Sleutel Steven , De Neve Stefaan , Hofman Georges , Boeckx Pascal , Beheydt Daan , Van Cleemput Oswald , Mestdagh Inge , Lootens Peter , Carlier Lucien , Van Camp Nancy , Verbeeck Hans , Vande Walle Inge , Samson Roeland , Lust Noël , Lemeur Raoul 
Published: July 2003

AbstractEvaluations of soil organic carbon (SOC) stocks are often based on assigning a carbon density to each one of a number of ecosystems or soil classes considered, using data from soil profiles within these categories. A better approach, in which the use of classification methods by which extrapolation of SOC data to larger areas is avoided, can only be used if enough data are available at a sufficiently small scale. Over 190 000 SOC measurements (0–24 cm) have been made in the Flemish cropland (the Northern part of Belgium) in the 1989–2000 period. These SOC data were grouped into 3‐year periods and as means plus standard deviation per (part of) community (polygons). This large dataset was used to calculate SOC stocks and their evolution with time, without data extrapolation. Using a detailed soil map, larger spatial groups of polygons were created based on soil texture and spatial location. Linear regression analysis showed that in the entire study area, SOC stocks had decreased or at best had remained stable. In total, a yearly decrease of 354 kton OC yr−1 was calculated, which corresponds with a net CO2 emission of 1238 kton CO2 yr−1. Specific regions with a high carbon sequestration potential were identified, based on SOC losses during the 1989–2000 period and the mean 1999 SOC content, compared to the average SOC content of soils in Flanders with a similar soil texture. When restoring the SOC stocks to their 1990 level, we estimated the carbon sequestration potential of the Flemish cropland soils to be some 300 kton CO2 yr−1 at best, which corresponds to a 40‐year restoration period. In conclusion, we can say that in regions where agricultural production is very intense, carbon sequestration in the cropland may make only a very modest contribution to a country's effort to reduce greenhouse gas emissions.
Association between Opuntia species invasion and changes in land‐cover in the Mediterranean region
Authors: Vilà Montserrat , Burriel José Angel , Pino Joan , Chamizo Joan , Llach Emma , Porterias Montserrat , Vives Miquel 
Published: July 2003

AbstractIn Mediterranean regions, biological invasions pose a major threat to the conservation of native species and the integrity of ecosystems. In addition, changes in land‐cover are a widespread phenomenon in Mediterranean regions, where an increase in urban areas and major changes from agricultural abandonment to shrub encroachment and afforestation are occurring. However, the link between biological invasions and changes in land‐cover has scarcely been analyzed. We conducted a regional survey of the distribution of the two alien prickly‐pear cacti Opuntia maxima and O. stricta in Cap de Creus (Catalonia, Spain) and related patterns of invasion to spatially explicit data on land‐cover/change from 1973 to 1993 to test the hypotheses that the two Opuntia species invade areas that have experienced large land‐cover transformations. We found that Opuntia invasion is particularly high in shrublands and woodlands located near urban areas. O. maxima are over‐represented in the shrublands and O. stricta in the woodlands that were former crops. Crop coverage has dropped by 71% in this 20‐year period. This study highlights the role of past land‐cover in understanding the present distribution of plant invasions.
In situlitter decomposition and litter quality in a Mojave Desert ecosystem: effects of elevated atmospheric CO2and interannual climate variability
Authors: Weatherly Heather E. , Zitzer Stephen F. , Coleman James S. , Arnone John A. 
Published: July 2003

AbstractRising atmospheric CO2has been predicted to reduce litter decomposition as a result of CO2‐induced reductions in litter quality. However, available data have not supported this hypothesis in mesic ecosystems, and no data are available for desert or semi‐arid ecosystems, which account for more than 35% of the Earth's land area. The objective of our study was to explore controls on litter decomposition in the Mojave Desert using elevated CO2and interannual climate variability as driving environmental factors. In particular, we sought to evaluate the extent to which decomposition is modulated by litter chemistry (C:N) and litter species and tissue composition. Naturally senesced litter was collected from each of nine 25 m diameter experimental plots, with six plots exposed to ambient [CO2] or 367 μL CO2 L−1and three plots continuously fumigated with elevated [CO2] (550 μL CO2 L−1) using FACE technology beginning in April 1997. All litter collected in 1998 (a wet, or El Niño year; 306 mm precipitation) was pooled as was litter collected in 1999 (a dry year; 94 mm). Samples were allowed to decompose for 4 and 12 months starting in May 2001 in mesh litterbags in the locations from which litter was collected. Decomposition of litter produced under elevated CO2and ambient CO2did not differ. Litter produced in the wetter year showed more rapid initial decomposition (over the first 4 months) than that produced in the drier year (27±2% yr−1or 7.8±0.7 g m−2 yr−1for 1998 litter; 18±3% yr−1or 2.2±0.4 g m−2 yr−1for 1999 litter). C:N ratios of litter produced under elevated CO2(wet year: 37±0.5; dry year: 42±2.5) were higher than those of litter produced under ambient CO2(wet year: 34±1.1; dry year: 35±1.4). Litter production in the wet year (amb. CO2: 25.1±1.1 g m−2 yr−1; elev. CO2: 35.0±1.1 g m−2 yr−1) was more than twice as high as that in the dry year (amb. CO2: 11.6±1.7 g m−2, elev. CO2: 13.3±3.4 g m−2), and contained a greater proportion ofLycium pallidumand a lower proportion ofLarrea tridentatathan litter produced in the dry year. Decomposition, viewed across all treatments, decreased with increasing C:N ratios, decreased with increasing proportions ofLarrea tridentataand increased with increasing proportions ofLycium pallidumandLycium andersonii. Because litter C:N did not vary by litter production year, and CO2did not alter decomposition or litter species/tissue composition, it is likely that the impact of year‐to‐year variation in precipitation on the proportion of key plant species in the litter may be the most important way in which litter decomposition will be modulated in the Mojave Desert under future rising atmospheric CO2.
Nitrous oxide emissions from grass swards during the eighth year of elevated atmospheric pCO2 (Swiss FACE)
Authors: Baggs E. M. , Richter M. , Hartwig U. A. , Cadisch G. 
Published: July 2003

AbstractEmissions of N2O were measured during the growth season over a year from grass swards under ambient (360 μL L−1) and elevated (600 μL L−1) CO2 partial pressures at the Free Air Carbon dioxide Enrichment (FACE) experiment, Eschikon, Switzerland. Measurements were made following high (56 g N m−2 yr−1) and low (14 g N m−2 yr−1) rates of fertilizer application, split over 5 re‐growth periods, to Lolium perenne, Trifolium repens and mixed Lolium/Trifolium swards. Elevated pCO2 increased annual emissions of N2O from the high fertilized Lolium and mixed Lolium/Trifolium swards resulting in increases in GWP (N2O emissions) of 179 and 111 g CO2 equivalents m−2, respectively, compared with the GWP of ambient pCO2 swards, but had no significant effect on annual emissions from Trifolium monoculture swards. The greater emissions from the high fertilized elevated pCO2Lolium swards were attributed to greater below‐ground C allocation under elevated pCO2 providing the energy for denitrification in the presence of excess mineral N. An annual emission of 959 mg N2O‐N m−2 yr−1 (1.7% of fertilizer N applied) was measured from the high fertilized Lolium sward under elevated pCO2. The magnitude of emissions varied throughout the year with 84% of the total emission from the elevated pCO2Lolium swards measured during the first two re‐growths (April–June 2001). This was associated with higher rainfall and soil water contents at this time of year. Trends in emissions varied between the first two re‐growths (April–June 2001) and the third, fourth and fifth re‐growths (late June–October 2000), with available soil NO3− and rainfall explaining 70%, and soil water content explaining 72% of the variability in N2O in these periods, respectively. Caution is therefore required when extrapolating from short‐term measurements to predict long‐term responses to global climate change. Our findings are of global significance as increases in atmospheric concentrations of CO2 may, depending on sward composition and fertilizer management, increase greenhouse gas emissions of N2O, thereby exacerbating the forcing effect of elevated CO2 on global climate. Our results suggest that when applying high rates of N fertilizer to grassland systems, Trifolium repens swards, or a greater component of Trifolium in mixed swards, may minimize the negative effect of continued increasing atmospheric CO2 concentrations on global warming.
The effect of vascular plants on carbon turnover and methane emissions from a tundra wetland
Authors: Ström Lena , Ekberg Anna , Mastepanov Mikhail , Røjle Christensen Torben 
Published: July 2003

AbstractThis paper investigates how vascular plants affect carbon flow and the formation and emission of the greenhouse gas methane (CH4) in an arctic wet tundra ecosystem in NE Greenland. We present a field experiment where we studied, in particular, how species‐specific root exudation patterns affect the availability of acetate, a hypothesized precursor of CH4 formation. We found significantly higher acetate formation rates in the root vicinity of Eriophorum scheuchzeri compared with another dominating sedge in the wetland, i.e. Dupontia psilosantha. Furthermore a shading treatment, which reduced net photosynthesis, resulted in significantly decreased formation rates of acetate. We also found that the potential CH4 production of the peat profile was highly positively correlated to the concentration of acetate at the respective depths, whereas it was negatively correlated to the concentration of total dissolved organic carbon. This suggests that acetate is a substrate of importance to the methanogens in the studied ecosystem and that acetate concentration in this case can serve as a predictor of substrate quality. To further investigate the importance of acetate as a predecessor to CH4, we brought an intact peat‐plant monolith system collected at the field site in NE Greenland to the laboratory, sealed it hermetically and studied the decomposition of 14C‐labelled acetate injected at the depth of methanogenic activity. After 4 h, 14CH4 emission from the monolith could be observed. In conclusion, allocation of recently fixed carbon to the roots of certain species of vascular plants affects substrate quality and influence CH4 formation.
Substantial labile carbon stocks and microbial activity in deeply weathered soils below a tropical wet forest
Authors: Veldkamp Edzo , Becker Anja , Schwendenmann Luitgard , Clark Deborah A. , Schulte‐Bisping Hubert 
Published: July 2003

AbstractContrary to large areas in Amazonia of tropical moist forests with a pronounced dry season, tropical wet forests in Costa Rica do not depend on deep roots to maintain an evergreen forest canopy through the year. At our Costa Rican tropical wet forest sites, we found a large carbon stock in the subsoil of deeply weathered Oxisols, even though only 0.04–0.2% of the measured root biomass (>2 mm diameter) to 3 m depth was below 2 m. In addition, we demonstrate that 20% or more of this deep soil carbon (depending on soil type) can be mobilized after forest clearing for pasture establishment. Microbial activity between 0.3 and 3 m depth contributed about 50% to the microbial activity in these soils, confirming the importance of the subsoil in C cycling. Depending on soil type, forest clearing for pasture establishment led from no change to a slight addition of carbon in the topsoil (0–0.3 m depth). However, this effect was countered by a substantial loss of C stocks in the subsoil (1–3 m depth). Our results show that large stocks of relatively labile carbon are not limited to areas with a prolonged dry season, but can also be found in deeply weathered soils below tropical wet forests. Forest clearing in such areas may produce unexpectedly high C losses from the subsoil.
Assessing the impact of land‐use change on soil C sequestration in agricultural soils by means of organic matter fractionation and stable C isotopes
Authors: Del Galdo Ilaria , Six Johan , Peressotti Alessandro , Francesca Cotrufo M. 
Published: July 2003

AbstractWithin the framework of the Kyoto Protocol, the potential mitigation of greenhouse gas emissions by terrestrial ecosystems has placed focus on carbon sequestration following afforestation of former arable land. Central to this soil C sequestration are the dynamics of soil organic matter (SOM). In North Eastern Italy, a mixed deciduous forest was planted on continuous maize field soil with a strong C4 isotopic C signature 20 years ago. In addition, a continuous maize field and a relic of the original permanent grassland were maintained at the site, thus offering the opportunity to compare the impacts on soil C dynamics by conventional agriculture, afforestation and permanent grassland. Soil samples from the afforested, grassland and agricultured systems were separated in three aggregate size classes, and inter‐ vs. intra‐aggregate particulate organic matter was isolated. All fractions were analyzed for their C content and isotopic signature. The distinct 13C signature of the C derived from maize vegetation allowed the calculation of proportions of old vs. forest‐derived C of the physically defined fractions of the afforested soil. Long‐term agricultural use significantly decreased soil C content (−48%), in the top 10 cm, but not SOM aggregation, as compared to permanent grassland. After 20 years, afforestation increased the total amount of soil C by 23% and 6% in the 0–10 and in the 10–30 cm depth layer, respectively. Forest‐derived carbon contributed 43% and 31% to the total soil C storage in the afforested systems in the 0–10 and 10–30 cm depths, respectively. Furthermore, afforestation resulted in significant sequestration of new C and stabilization of old C in physically protected SOM fractions, associated with microaggregates (53–250 μm) and silt&clay (<53 μm).