bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uncertainty in estimating land use and management impacts on soil organic carbon storage for US agricultural lands between 1982 and 1997
Authors: Ogle Stephen M. , Jay Breidt F. , Eve Marlen D. , Paustian Keith 
Published: November 2003

AbstractUncertainty was quantified for an inventory estimating change in soil organic carbon (SOC) storage resulting from modifications in land use and management across US agricultural lands between 1982 and 1997. This inventory was conducted using a modified version of a carbon (C) accounting method developed by the Intergovernmental Panel on Climate Change (IPCC). Probability density functions (PDFs) were derived for each input to the IPCC model, including reference SOC stocks, land use/management activity data, and management factors. Change in C storage was estimated using a Monte‐Carlo approach with 50 000 iterations, by randomly selecting values from the PDFs after accounting for dependencies in the model inputs. Over the inventory period, mineral soils had a net gain of 10.8 Tg C yr−1, with a 95% confidence interval ranging from 6.5 to 15.3 Tg C yr−1. Most of this gain was due to setting‐aside lands in the Conservation Reserve Program. In contrast, managed organic soils lost 9.4 Tg C yr−1, with a 95% confidence interval ranging from 6.4 to 13.3 Tg C yr−1. Combining these gains and losses in SOC, US agricultural soils accrued 1.3 Tg C yr−1 due to land use and management change, with a 95% confidence interval ranging from a loss of 4.4 Tg C yr−1 to a gain of 6.9 Tg C yr−1. Most of the uncertainty was attributed to management factors for tillage, land use change between cultivated and uncultivated conditions, and C loss rates from managed organic soils. Based on the uncertainty, we are not able to conclude with 95% confidence that change in US agricultural land use and management between 1982 and 1997 created a net C sink for atmospheric CO2.
Natural disturbances in the European forests in the 19th and 20th centuries
Authors: Schelhaas Mart‐Jan , Nabuurs Gert‐Jan , Schuck Andreas 
Published: November 2003

AbstractThis paper, based on a literature review, presents a quantitative overview of the role of natural disturbances in European forests from 1850 to 2000. Such an overview provides a basis for modelling the possible impacts of climate change and enables one to assess trends in disturbance regimes in different countries and/or periods. Over the period 1950–2000, an annual average of 35 million m3 wood was damaged by disturbances; there was much variation between years. Storms were responsible for 53% of the total damage, fire for 16%, snow for 3% and other abiotic causes for 5%. Biotic factors caused 16% of the damage, and half of this was caused by bark beetles. For 7% of the damage, no cause was given or there was a combination of causes. The 35 million m3 of damage is about 8.1% of the total fellings in Europe and about 0.15% of the total volume of growing stock. Over the period 1961–2000, the average annual area of forest fires was 213 000 ha, which is 0.15% of the total forest area in Europe. Most types of damage seem to be increasing. This is partly an artefact of the improved availability of information. The most likely explanations for an increase in damage from disturbances are changes in forest management and resulting changes in the condition of the forest. Forest area, average volume of growing stock and average stand age have increased considerably, making the forest more vulnerable and increasing the resources that can be damaged. Since forest resources are expected to continue to increase, it is likely that damage from disturbances will also increase in future.
North Sea cod and climate change – modelling the effects of temperature on population dynamics
Authors: Clark Robin A. , Fox Clive J. , Viner David , Livermore Matthew 
Published: November 2003

AbstractIn order to examine the likely impacts of climate change on fish stocks, it is necessary to couple the output from large‐scale climate models to fisheries population simulations. Using projections of future North Sea surface temperatures for the period 2000–2050 from the Hadley General Circulation Model, we estimate the likely effects of climate change on the North Sea cod population. Output from the model suggests that increasing temperatures will lead to an increased rate of decline in the North Sea cod population compared with simulations that ignore environmental change. Although the simulation developed here is relatively simplistic, we demonstrate that inclusion of environmental factors in population models can markedly alter one's perception of how the population will behave. The development of simulations incorporating environment effects will become increasingly important as the impacts of climate change on the marine ecosystem become more pronounced.
Impacts of changing climate and atmospheric deposition on N and S drainage losses from a forested watershed of the Adirondack Mountains, New York State
Authors: Park Ji‐Hyung , Mitchell Myron J. , McHale Patrick J. , Christopher Sheila F. , Meyers Tilden P. 
Published: November 2003

AbstractBiogeochemical responses to changing climate and atmospheric deposition were investigated using nitrogen (N) and sulfur (S) mass balances, including dry deposition and organic solutes in the Arbutus Lake watershed in the Adirondack Mountains, New York State. Long‐term monitoring of wet‐only precipitation (NADP/NTN, 1983–2001) and dry deposition (AIRMoN, 1990–2001) at sites adjacent to the watershed showed that concentrations of SO42− in precipitation, SO42− in particles,and SO2 vapor all declined substantially (P<0.005) in contrast to no marked temporal changes observed for most N constituents (NH4+ in precipitation, HNO3 vapor, and particulate NO3−), except for NO3− in precipitation, which showed a small decrease in the late 1990s. From 1983 to 2001, concentrations of SO42− in the lake outlet significantly decreased (−2.1 μeq L−1 yr−1, P<0.0001), whereas NO3− and dissolved organic N (DON) concentrations showed no consistent temporal trends. With the inclusion of dry deposition and DON fluxes into the mass balance, the retained portion of atmospheric N inputs within the main subcatchment increased from 37% to 60%. Sulfur outputs greatly exceeded inputs even with the inclusion of dry S deposition, while organic S flux represented another source of S output, implying substantial internal S sources. A significant relationship between the annual mean concentrations of SO42− in lake discharge and wet deposition over the last two decades (r=0.64, P<0.01) suggested a considerable influence of declining S deposition on surface water SO42− concentrations, despite substantial internal S sources. By contrast, interannual variations in both NO3− concentrations and fluxes in lake discharge were significantly related to year‐to‐year changes in air temperature and runoff. Snowmelt responses to winter temperature fluctuations were crucial in explaining large portions of interannual variations in watershed NO3− export during the months preceding spring snowmelt (especially, January–March). Distinctive response patterns of monthly mean concentrations of NO3− and DON in the major lake inlet to seasonal changes in air temperature also suggested climatic regulation of seasonal patterns in watershed release of both N forms. The sensitive response of N drainage losses to climatic variability might explain the synchronous patterns of decadal variations in watershed NO3− export across the northeastern USA.
Detection of process‐related changes in plant patterns at extended spatial scales during early dryland desertification
Authors: Ares Jorge , Del Valle Héctor , Bisigato Alejandro 
Published: November 2003

AbstractArid and semiarid shrublands occupy extensive land areas over the world, are susceptible to desertification by anthropic use and can contribute to regional climate change. These prompt the interest to monitor and evaluate these lands adequately in order to detect early stages of degradation. Evaluation topics must refer to biology‐relevant characteristics of these systems, while simultaneously satisfying sampling consistency over extended landscape areas. We present an analysis of process‐relevant parameters related to changes in the spatial arrangement of the plant canopy of shrublands inferred from high‐resolution panchromatic aerial photos and Interferometric Synthetic Aperture Radar imagery. We obtained low‐altitude images systematically located along several gradients of land‐use intensity in a Patagonian Monte shrubland in Argentina. Images were digitized to spatial resolutions ranging from 0.09 to 0.72 m (pixel size) and the average values and an‐isotropic characteristics of the plant canopy patterns were quantified by means of a Fourier metric. We used radar‐derived imagery to overlay the panchromatic images on a digital elevation model in order to study the correspondence of potential runoff patterns and the spatial arrangement of plants. We related an‐isotropic features of the plant canopy images to the prevailing wind regime. Observed trends were further interpreted on the basis of a spatial‐explicit simulation model describing the dynamics of the main functional groups in the plant community. We conclude that early stages of anthropic‐driven dryland degradation in the Patagonian Monte can be characterized by the incipient un‐coupling of spatial vegetation patterns from those of runoff at a landscape scale, and a progressive coupling to the spatial pattern of the wind regime. The method and metrics we present can be used to quantify early desertification changes in other similar drylands at extended spatial scales.
Biotic and abiotic immobilization of ammonium, nitrite, and nitrate in soils developed under different tree species in the Catskill Mountains, New York, USA
Authors: Fitzhugh Ross D. , Lovett Gary M. , Venterea Rodney T. 
Published: November 2003

AbstractNitrogen retention in soil organic matter (SOM) is a key process influencing the accumulation and loss of N in forest ecosystems, but the rates and mechanisms of inorganic N retention in soils are not well understood. The primary objectives of this study were to compare ammonium (NH4+), nitrite (NO2−), and nitrate (NO3−) immobilization among soils developed under different tree species in the Catskill Mountains of New York State, and to determine the relative roles of biotic or abiotic processes in soil N retention. A laboratory experiment was performed, where 15N was added as NH4+, NO2−, or NO3− to live and mercury‐treated O horizon soils from three tree species (American beech, northern red oak, sugar maple), and 15N recoveries were determined in the SOM pool. Mercuric chloride was used to treat soils as this chemical inhibits microbial metabolism without significantly altering the chemistry of SOM. The recovery of 15N in SOM was almost always greater for NH4+ (mean 20%) and NO2− (47%) than for NO3− (10%). Ammonium immobilization occurred primarily by biotic processes, with mean recoveries in live soils increasing from 9% at 15 min to 53% after 28 days of incubation. The incorporation of NO2− into SOM occurred rapidly (<15 min) via abiotic processes. Abiotic immobilization of NO2− (mean recovery 58%) was significantly greater than abiotic immobilization of NH4+ (7%) or NO3− (7%). The incorporation of NO2− into SOM did not vary significantly among tree species, so this mechanism likely does not contribute to differences in soil NO3− dynamics among species. As over 30% of the 15NO2− label was recovered in SOM within 15 min in live soils, and the products of NO2− incorporation into SOM remained relatively stable throughout the 28‐day incubation, our results suggest that NO2− incorporation into SOM may be an important mechanism of N retention in forest soils. The importance of NO2− immobilization for N retention in field soils, however, will depend on the competition between incorporation into SOM and nitrification for transiently available NO2−. Further research is required to determine the importance of this process in field environments.
Ondansetron does not prevent pruritus induced by low‐dose intrathecal fentanyl
Authors: Korhonen A. M. , Valanne J. V. , Jokela R. M. , Ravaska P. , Korttila K. 
Published: November 2003

Background:  Addition of an opioid to low‐dose spinal anesthesia with bupivacaine improves the quality and success of anesthesia. However, the intrathecal fentanyl‐induced pruritus is as high as 75%. We hypothesized that after administration of 4 or 8 mg of prophylactic IV ondansetron, the incidence of pruritus induced by low‐dose intrathecal fentanyl would be significantly lower than after placebo.Methods:  In this double‐blind study, 90 outpatients undergoing knee arthroscopy received 3 mg of bupivacaine + 10 µg fentanyl intrathecally. Before spinal puncture, the patients received randomly either saline (P) or ondansetron 4 mg (O4) or 8 mg (O8) IV. They were asked about pruritus frequently, and they estimated its severity on a scale of 0–10.Results:  There was no difference in the incidence of pruritus between the three groups: pruritus occurred in 17 (57%), in 21 (75%) and in 19 patients (70%) in P, O4 and O8 groups, respectively. The pruritus was mostly mild. Four patients in the placebo group, three in the O4 and four patients in the O8 groups considered it severe. One patient in each group requested treatment for pruritus; after IV naloxone their pruritus was relieved. Neither time to pruritus nor duration of pruritus differed between the groups. One patient in each group developed a long‐lasting (>10 h) pruritus.Conclusions:  After prophylactic administration of 4 or 8 mg of ondansetron IV, the incidence, duration and severity of pruritus were similar to placebo. Ondansetron does not prevent pruritus induced by low‐dose intrathecal fentanyl.
Screening for mast cell tryptase and serum IgE antibodies in 18 patients with anaphylactic shock during general anaesthesia
Authors: Dybendal T. , Guttormsen A. B. , Elsayed S. , Askeland B. , Harboe T. , Florvaag E. 
Published: November 2003

Background:  In the perioperative setting multiple agents can cause anaphylaxis. Often the reactions are dramatic, and due to their lifethreatening potential it is crucial that the responsible agent is identified in order to avoid future adverse reactions. The aim of the present study was to measure the concentration of serum mast cell tryptase (MCT), to investigate the prevalence of serum IgE antibodies against ammonium groups, choline, morphine, suxamethonium, thiopentone and latex and to perform skin prick tests (SPTs) in 18 patients experiencing an anaphylactic reaction during induction of general anaesthesia.Methods:  Serum samples from 18 patients with an anaphylactic reaction during general anaesthesia were analyzed for MCT and specific IgE against ammonium groups, choline, morphine, suxamethonium, thiopentone and latex. Skin prick tests were performed in 11 out of 18 patients.Results:  Ten patients had elevated MCT levels and specific IgE against ammonium ion, morphine and (with the exception of patient nos 3, 9 and 10) suxamethonium. Seven of these patients had positive SPTs to suxamethonium. One of the patients tested positive to latex in addition to suxamethonium. Two patients showed elevated MCT, while specific IgE against the drugs tested was not detected. Three patients tested positive to ammonium ion, morphine and suxamethonium, but negative to MCT. Three patients tested negative to both MCT and specific IgE.Conclusions:  Fifteen out of 18 sera tested positive for MCT and/or specific IgE against neuromuscular blocking drugs (NMBDs). Ten of the 18 patients experienced an IgE‐mediated anaphylactic reaction to NMBDs during anaesthesia, verified by detection of specific IgE and elevated levels of MCT.
Preparing teams for low‐frequency emergencies in Norwegian hospitals
Authors: Wisborg T. , Rønning T. H. , Beck V. B. , Brattebø G. 
Published: November 2003

Background:  Medical emergencies and major trauma require optimal team function. Leadership, co‐operation and communication are the most essential issues. Due to low caseloads such emergencies occur rarely in most Norwegian hospitals. Team training of personnel between real emergencies is expected to improve performance in comparable settings. Most hospitals have cardiac arrest teams, but it is known that the training of such multiprofessional teams varies widely. We wanted to know if this also was the case for trauma teams and resuscitation teams for newborns.Methods:  A telephone survey of training practices in all the Norwegian hospitals with acute cover was conducted in 2002. Information was obtained on whether trauma teams and neonatal resuscitation teams had participated in practical multiprofessional training during the previous 6 or 12 months.Results:  Information was obtained from all 50 hospitals. Of the acute care hospitals, 30% had trained their trauma teams during the previous 6 months, and an additional 18% when considering the previous year, while 38% of neonatal wards had multiprofessional training during the previous 6 months, and additionally 13% had had training during the previous year. Additionally four neonatal wards had had regular training of nurses only. More than 80% of all respondents judged regular team training to be achievable, and none considered this training impossible.Conclusion:  Only half the Norwegian acute care hospitals reported at least yearly training of trauma and neonatal resuscitation teams. Regular team training represents an underused potential to improve handling of low‐frequency emergencies.
Perioperative changes in cerebral ischemic markers in the cerebrospinal fluid after preoperative nimodipine treatment
Authors: Oehmke M. J. , Schirrmeister D. , Kuhn D. F. M. , Fritz T. , Engel J. , Hempelmann G. 
Published: November 2003

Background:  Elderly patients with previous organ damage are at risk for minor neurologic deficits after major surgery. Spinal catheter analgesia is used whenever possible in this group and enables regular cerebrospinal fluid (CSF) sampling. Nimodipine, a calcium blocker, may have neuroprotective effects. We examined whether preoperative treatment with nimodipine affects ischemic markers in the CSF during extracranial surgery.Methods:  We performed a prospective, randomized, placebo‐controlled, double‐blind study in patients (ASA III or IV, 65–85 years) that underwent elective implantation surgery of the hip joint with intrathecal catheter anesthesia. Starting 15 h before surgery, patients received either 30 µg kg−1 h−1 of nimodipine (n = 20) or 0.9% saline solution (placebo, n = 23) as a central venous infusion. The concentrations of neuron‐specific enolase, hypoxanthine, creatine‐kinase, lactate and pH in the CSF were determined before and immediately after surgery as well as 6 and 24 h after surgery.Results:  Before surgery, the baseline CSF pH was normal in all patients. Immediately after surgery it fell significantly to 7.08 ± 0.29 in the placebo group and non‐significantly to 7.27 ± 0.38 in the treatment group; all values were normalized at 6 and 24 h after surgery in both groups. In the placebo group, lactate levels rose significantly from 1.48 ± 0.28 mmol l−1 before surgery to 1.77 ± 0.27 mmol l−1 immediately after surgery, and to 2.03 ± 0.32 mmol l−1 24 h after surgery. In the treatment group, lactate concentrations remained stable up to 6 h after surgery (1.55–1.62 mmol l−1), while an increase to 2.10 ± 0.48 mmol l−1 was observed 24 h after the operation. Neuron‐specific enolase, hypo‐xanthine and creatine‐kinase showed no change in either group.Conclusion:  In conclusion, preoperative nimodipine treatment reduced intraoperative CSF acidosis and delayed surgery‐related increases in lactate concentration in the CSF by several hours in elderly, comorbid patients at risk for minor postoperative neurologic deficits.
Hemodynamic effects of a continuous infusion of levosimendan in critically ill patients with cardiogenic shock requiring catecholamines
Authors: Delle Karth G. , Buberl A. , Geppert A. , Neunteufl T. , Huelsmann M. , Kopp C. , Nikfardjam M. , Berger R. , Heinz G. 
Published: November 2003

Background:  Levosimendan, a novel inodilator, has been shown to improve hemodynamic function in patients with decompensated heart failure with preserved arterial blood pressure. Data on its use in patients with cardiogenic shock are rare. The present series describes the 24‐h hemodynamic effects of levosimendan as add‐on therapy in desperately ill patients with cardiogenic shock requiring catecholamines.Methods:  Ten patients with cardiogenic shock received levosimendan as continuous infusion of 0.1 µg kg−1 min−1 for 24 h. The patients were otherwise unselected. Hemodynamic measurements were routinely performed at baseline (time 0) and at 1, 8, 16 and 24 h after start of levosimendan (LS) using a Swan‐Ganz thermodilution catheter.Results:  During the levosimendan infusion there was a significant increase in cardiac index from 1.8 ± 0.4 to 2.4 ± 0.6 L*min−1*m−2 (P = 0.023) and a significant decrease in systemic vascular resistance from 1559 ± 430 to 1109 ± 202 dyn*s*cm−5 (P = 0.001), respectively. Changes in catecholamine dose, and in systolic and diastolic blood pressure were not significant. Given the individual response to LS, 8/10 patients showed an increase in left ventricular stroke work index under reduced or roughly unchanged preload conditions after 8 h.Conclusion:  This series shows that a LS infusion is feasible and able to improve hemodynamics in severely compromized, critically ill patients with cardiogenic shock requiring catecholamine therapy. Its potential advantages when compared with other inotropes are unclear. To clarify the potential role of LS in this clinical setting randomized controlled trials on hemodynamic and mortality endpoints are needed.
Technical note High‐cycle fatigue crack initiation and propagation behaviour of high‐strength sprin steel wires
Authors: Wang Q. Y. , Berard J. Y. , Rathery S. , Bathias C. 
Published: November 2003

An attempt has been made to characterize high‐cycle fatigue behaviour of high‐strength spring steel wire by means of an ultrasonic fatigue test and analytical techniques. Two kinds of induction‐tempered ultra‐high‐strength spring steel wire of 6.5 mm in diameter with a tensile strength of 1800 MPa were used in this investigation.The fatigue strength of the steel wires between 106 and 109 cycles was determined at a load ratio R = −1. The experimental results show that fatigue rupture can occur beyond 107 cycles. For Cr–V spring wire, the stress–life (S–N ) curve becomes horizontal at a maximum stress of 800 MPa after 106 cycles, but the S–N curve of the Cr–Si steel continues to drop at a high number of cycles (>106 cycles) and does not exhibit a fatigue limit, which is more correctly described by a fatigue strength at a given number of cycles. By using scanning electron microscopy (SEM), the crack initiation and propagation behaviour have been examined. Experimental and analytical techniques were developed to better understand and predict high‐cycle fatigue life in terms of crack initiation and propagation. The results show that the portion of fatigue life attributed to crack initiation is more than 90% in the high‐cycle regime for the steels studied in this investigation.