bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biogenic VOC emissions from forested Amazonian landscapes
Authors: Greenberg James P. , Guenther Alex B. , Pétron Gabrielle , Wiedinmyer Christine , Vega Oscar , Gatti Luciana V. , Tota Julio , Fisch Gilberto 
Published: May 2004

AbstractA tethered balloon‐sampling platform was used to study biogenic volatile organic compounds (BVOCs) in the atmospheric boundary layer in three distinct moist tropical forest ecoregions, as well as an extensive pasture area, in Amazonia. Approximately 24–40 soundings, including as many as four VOC samples collected simultaneously at various altitudes, were made at each site. Concentrations in the mixed layer increased during morning hours and were relatively constant midday through afternoon. Since most important meteorological and chemical parameters were very similar among the sites during the measurement periods, a BVOC canopy emission model was used with a model of the chemistry of the boundary layer to reproduce the atmospheric concentrations observed. The simulations indicated significantly different midday landscape isoprene and α‐pinene emission rates for the three forest ecoregions (2200, 5300, 9800 μg m−2 h−1 isoprene and 90, 120, and 180 μg m−2 h−1α‐pinene for the three moist forest ecoregions studied, respectively). The differences in emissions among the ecoregions may be attributed to the species composition, which were markedly different and in which the percentage of isoprene and terpene emitting species also differed significantly.
Modeling changes in soil organic matter in Amazon forest to pasture conversion with the Century model
Authors: Cerri Carlos Eduardo P. , Paustian Keith , Bernoux Martial , Victoria Reynaldo L. , Melillo Jerry M. , Cerri Carlos C. 
Published: May 2004

AbstractLand use and land cover changes in the Brazilian Amazon region have major implications for regional and even global carbon cycling. We analyzed the effects of the predominant land use change, conversion of tropical forest to pasture, on total soil C and N, using the Century ecosystem model and data collected from the Nova Vida ranch, Western Brazilian Amazon. We estimated equilibrium organic matter levels, plant productivity and residue carbon inputs under native forest conditions, then simulated deforestation following the slash and burn procedure. Soil organic matter dynamics were simulated for pastures established in 1989, 1987, 1983, 1979, 1972, 1951, and 1911. Using input data from the Nova Vida ranch, the Century model predicted that forest clearance and conversion to pasture would cause an initial decline in soil C and N stocks, followed by a slow rise to levels exceeding those under native forest. Simulated soil total C and N levels (2500 g C m−2 and 245 g N m−2 in the 0–20 cm layer) prior to conversion to pasture were close to those measured in the native forest. Simulated above‐ and below‐ground biomass for the forest and pasture were comparable with literature values from this region. The model predicted the long‐term changes in soil C and N under pasture inferred from the pasture chronosequence, but there was considerable variation in soil C stocks for pastures <20 years in age. Differences in soil texture between pastures were relatively small and could not account for much of the variability between different pastures of similar ages, in either the measured or simulated data. It is likely that much of the variability in C stocks between pastures of similar ages is related to initial C stocks immediately following deforestation and that this was the largest source of variability in the chronosequence. Internal C cycling processes in Century were evaluated using measurements of microbial biomass and soil δ13C. The relative magnitude and long‐term trend in microbial biomass simulated by the model were consistent with measurements. The close fit of simulated to measured values of δ13C over time suggests that the relative loss of forest‐derived C and its replacement by pasture‐derived C was accurately predicted by the model. After 80 years, almost 90% of the organic matter in the top 20 cm was pasture derived. While our analysis represents a single ‘case study’ of pasture conversion, our results suggest that modeling studies in these pasture systems can help to evaluate the magnitude of impacts on C and N cycling, and determine the effect of management strategies on pasture sustainability.
Teleconnection between tree growth in the Amazonian floodplains and the El Niño–Southern Oscillation effect
Authors: Schöngart Jochen , Junk Wolfgang J. , Piedade Maria Teresa F. , Ayres José Marcio , Hüttermann Aloys , Worbes Martin 
Published: May 2004

AbstractThere is a limited knowledge about the El Niño–Southern Oscillation (ENSO) effects on the Amazon basin, the world's largest tropical rain forest and a major factor in the global carbon cycle. Seasonal precipitation in the Andean watershed annually causes a several month‐long inundation of the floodplains along the Amazon River that induces the formation of annual rings in trees of the flooded forests. Radial growth of trees is mainly restricted to the nonflooded period and thus the ring width corresponds to its duration. This allows the construction of a tree‐ring chronology of the long‐living hardwood species Piranhea trifoliata Baill. (Euphorbiaceae). El Niño causes anomalously low precipitation in the catchment that results in a significantly lower water discharge of the Amazon River and consequently in an extension of the vegetation period. In those years tree rings are significantly wider. Thus the tree‐ring record can be considered as a robust indicator reflecting the mean climate conditions of the whole Western Amazon basin. We present a more than 200‐year long chronology, which is the first ENSO‐sensitive dendroclimatic proxy of the Amazon basin and permits the dating of preinstrumental El Niño events. Time series analyses of our data indicate that during the last two centuries the severity of El Niño increased significantly.
Simulating the response of land‐cover changes to road paving and governance along a major Amazon highway: the Santarém–Cuiabá corridor
Authors: Soares‐Filho Britaldo , Alencar Ane , Nepstad Daniel , Cerqueira Gustavo , Vera Diaz Maria del Carmen , Rivero Sérgio , Solórzano Luis , Voll Eliane 
Published: May 2004

AbstractThe spatial distribution of human activities in forest frontier regions is strongly influenced by transportation infrastructure. With the planned paving of 6000 km of highway in the Amazon Basin, agricultural frontier expansion will follow, triggering potentially large changes in the location and rate of deforestation. We developed a land‐cover change simulation model that is responsive to road paving and policy intervention scenarios for the BR‐163 highway in central Amazonia. This corridor links the cities of Cuiabá, in central Brazil, and Santarém, on the southern margin of the Amazon River. It connects important soybean production regions and burgeoning population centers in Mato Grosso State with the international port of Santarém, but 1000 km of this road are still not paved. It is within this context that the Brazilian government has prioritized the paving of this road to turn it into a major soybean exportation facility. The model assesses the impacts of this road paving within four scenarios: two population scenarios (high and moderate growth) and two policy intervention scenarios. In the ‘business‐as‐usual’ policy scenario, the responses of deforestation and land abandonment to road paving are estimated based on historical rates of Amazon regions that had a major road paved. In the ‘governance’ scenario, several plausible improvements in the enforcement of environmental regulations, support for sustainable land‐use systems, and local institutional capacity are invoked to modify the historical rates. Model inputs include data collected during expeditions and through participatory mapping exercises conducted with agents from four major frontier types along the road. The model has two components. A scenario‐generating submodel is coupled to a landscape dynamics simulator, ‘DINAMICA’, which spatially allocates the land‐cover transitions using a GIS database. The model was run for 30 years, divided into annual time steps. It predicted more than twice as much deforestation along the corridor in business‐as‐usual vs. governance scenarios. The model demonstrates how field data gathered along a 1000 km corridor can be used to develop plausible scenarios of future land‐cover change trajectories that are relevant to both global change science and the decision‐making process of governments and civil society in an important rainforest region.
High rates of net ecosystem carbon assimilation by Brachiara pasture in the Brazilian Cerrado
Authors: Santos Alexandre J.B. , Quesada Carlos A. , Da Silva Gabriela T. , Maia Jair F. , Miranda Heloisa S. , Carlos Miranda Antonio , Lloyd Jon 
Published: May 2004

AbstractTo investigate the consequences of land use on carbon and energy exchanges between the ecosystem and atmosphere, we measured CO2 and water vapour fluxes over an introduced Brachiara brizantha pasture located in the Cerrado region of Central Brazil. Measurements using eddy covariance technique were carried out in field campaigns during the wet and dry seasons. Midday CO2 net ecosystem exchange rates during the wet season were −40 μmol m−2 s−1, which is more than twice the rate found in the dry season (−15 μmol m−2 s−1). This was observed despite similar magnitudes of irradiance, air and soil temperatures. During the wet season, inferred rates of canopy photosynthesis did not show any tendency to saturate at high solar radiation levels, with rates of around 50 μmol m−2 s−1 being observed at the maximum incoming photon flux densities of 2200 μmol m−2 s−1. This contrasted strongly to the dry period when light saturation occurred with 1500 μmol m−2 s−1 and with maximum canopy photosynthetic rates of only 20 μmol m−2 s−1. Both canopy photosynthetic rates and night‐time ecosystem CO2 efflux rates were much greater than has been observed for cerrado native vegetation in both the wet and dry seasons. Indeed, observed CO2 exchange rates were also much greater than has previously been reported for C4 pastures in the tropics. The high rates in the wet season may have been attributable, at least in part, to the pasture not being grazed. Higher than expected net rates of carbon acquisition during the dry season may also have been attributable to some early rain events. Nevertheless, the present study demonstrates that well‐managed, productive tropical pastures can attain ecosystem gas exchange rates equivalent to fertilized C4 crops growing in the temperate zone.
The above‐ground coarse wood productivity of 104 Neotropical forest plots
Authors: Malhi Yadvinder , Baker Timothy R. , Phillips Oliver L. , Almeida Samuel , Alvarez Esteban , Arroyo Luzmilla , Chave Jerome , Czimczik Claudia I. , Fiore Anthony Di , Higuchi Niro , Killeen Timothy J. , Laurance Susan G. , Laurance William F. , Lewis Simon L. , Montoya Lina María Mercado , Monteagudo Abel , Neill David A. , Vargas Percy Núñez , Patiño Sandra , Pitman Nigel C.A. , Quesada Carlos Alberto , Salomão Rafael , Silva José Natalino Macedo , Lezama Armando Torres , Martínez Rodolfo Vásquez , Terborgh John , Vinceti Barbara , Lloyd Jon 
Published: May 2004

AbstractThe net primary production of tropical forests and its partitioning between long‐lived carbon pools (wood) and shorter‐lived pools (leaves, fine roots) are of considerable importance in the global carbon cycle. However, these terms have only been studied at a handful of field sites, and with no consistent calculation methodology. Here we calculate above‐ground coarse wood carbon productivity for 104 forest plots in lowland New World humid tropical forests, using a consistent calculation methodology that incorporates corrections for spatial variations in tree‐size distributions and wood density, and for census interval length. Mean wood density is found to be lower in more productive forests. We estimate that above‐ground coarse wood productivity varies by more than a factor of three (between 1.5 and 5.5 Mg C ha−1 a−1) across the Neotropical plots, with a mean value of 3.1 Mg C ha−1 a−1. There appear to be no obvious relationships between wood productivity and rainfall, dry season length or sunshine, but there is some hint of increased productivity at lower temperatures. There is, however, also strong evidence for a positive relationship between wood productivity and soil fertility. Fertile soils tend to become more common towards the Andes and at slightly higher than average elevations, so the apparent temperature/productivity relationship is probably not a direct one. Coarse wood productivity accounts for only a fraction of overall tropical forest net primary productivity, but the available data indicate that it is approximately proportional to total above‐ground productivity. We speculate that the large variation in wood productivity is unlikely to directly imply an equivalent variation in gross primary production. Instead a shifting balance in carbon allocation between respiration, wood carbon and fine root production seems the more likely explanation.
Epidemic soybean asthma and public health: new control systems and initial evaluation in Barcelona, 1996–98
Authors: Villalbí J R , Plasencia A , Manzanera R , Armengol R , Antó J M 
Published: May 2004

Objective:To evaluate the new measures adopted to control the risks from soybean unloading operations in the Port of Barcelona, after an episode of epidemic asthma in June 1996.Methods:After an initial cautionary suspension of all soybean unloading operations, they were subsequently resumed under restrictive criteria for time, flux, simultaneity, and meteorological conditions. Emission filtration systems based on either micro pore size filters or polytetrafluoroethylene membranes on tetratex filters showed promising results.Results:Allergen emission underwent a very important decrease to levels 95% to 98% lower. Emissions from the two plants with unloading operations are in the same order of magnitude as the processing plant that does not unload soybean. Allergen concentration levels presented fluctuations initially, but the new filters decreased mean values; despite increased unloading, allergen levels did not increase—mean allergen levels on unloading days (67 U/m3) and on days without unloading operations (63 U/m3) are similar. A panel of patients detected a cluster of increased symptoms during unloading operations on a day with suboptimal meteorological conditions and comparatively low allergen levels (225–415 U/m3). Since the June 1996 episode, no further asthma outbreak has been detected.Conclusions:The evaluation shows the effectiveness of the new filters in the control of soybean dust emission. With a systematic control programme, industrial soybean operations may function near urban centres without public health risks. These data may be useful in the development of future standards for allergenic agents.
Involvement in civil society groups: Is it good for your health?
Authors: Ziersch A M , Baum F E 
Published: May 2004

Study objective:To determine the involvement in civil society groups (CSGs) and the impact of this on health.Design:Case study, cross sectional, self completion questionnaire, and semi-structured interviews.Setting:Residents in two suburbs in Adelaide, South Australia.Participants:Every household (1038) received a questionnaire asking the adult with the next birthday to complete it. A total of 530 questionnaires were returned. Sixteen questionnaire respondents were also interviewed.Main results:279 (53%) questionnaire respondents had been involved in a CSG in the past 12 months, 190 (36%) in locally based CSGs, and 188 (35%) in CSGs outside the area. Eleven of the 16 interviewees had been involved in a CSG. A path analysis examined the relation between demographic variables, CSG involvement, and mental and physical health, as measured by the SF-12. Physical health was negatively associated with CSG involvement and older age, and positively associated with working full time or part time and higher education level. Mental health was positively associated with older age, working full time or part time, and higher income but negatively associated with having a child under 18, speaking a language other than English and higher education level. Very few interviewees made a direct link between CSGs and positive individual health outcomes, though some positive community level outcomes were noted. More consistent were reports of the detrimental effects of CSG involvement on mental and physical health.Conclusions:Involvement in CSGs was significant but not always positive for health. It is possible that CSG involvement is good for a community but not necessarily for the individual.
Employment status, employment conditions, and limiting illness: prospective evidence from the British household panel survey 1991–2001
Authors: Bartley M , Sacker A , Clarke P 
Published: May 2004

Objectives:To assess the relation of the incidence of, and recovery from, limiting illness to employment status, occupational social class, and income over time in an initially healthy sample of working age men and women.Methods:Cox proportional hazards models.Results:There were large differences in the risk of limiting illness according to occupational social class, with men and women in the least favourable employment conditions nearly four times more likely to become ill than those in the most favourable. Unemployment and economic inactivity also had a powerful effect on illness incidence. Limiting illness was not a permanent state for most participants in the study. Employment status was also related to recovery.Conclusions:Having secure employment in favourable working conditions greatly reduces the risk of healthy people developing limiting illness. Secure employment increases the likelihood of recovery. These findings have considerable implications for both health inequality and economic policies.
Combined Use of Erythropoietin and Granulocyte Colony-Stimulating Factor Does Not Decrease Blood Transfusion Requirements During Induction Therapy for High-Risk Neuroblastoma: A Randomized Controlled Trial
Authors: Wagner Lars M. , Billups Catherine A. , Furman Wayne L. , Rao Bhaskar N. , Santana Victor M. 
Published: May 2004

Purpose To evaluate the efficacy of recombinant erythropoietin (EPO) and granulocyte colony-stimulating factor (G-CSF) in reducing blood transfusion requirements and stimulating hematopoiesis in children with high-risk neuroblastoma. Patients and Methods Thirty-eight patients given six cycles of intensive induction chemotherapy for high-risk neuroblastoma were randomized to receive G-CSF (n = 20) or G-CSF + EPO (n = 18). Cytokines were given subcutaneously each day, starting 24 hours after each chemotherapy cycle and continuing until 48 hours before the start of the next cycle. The primary end point was the effect of EPO on total red cell transfusion requirements during induction therapy. Results Patients who received G-CSF + EPO had a higher red cell transfusion requirement (median, 161.0 mL/kg) than did those who received G-CSF alone (median, 106.6 mL/kg; P = .005). In addition, among patients given transfusions for hemoglobin ≤ 8 g/dL, those in the G-CSF + EPO group received more red cell transfusions than did those given G-CSF alone (median per patient, 10 v 8, respectively; P = .044). The two treatment groups had similar cumulative durations of neutropenia, incidences of febrile neutropenia, platelet transfusion requirements, and numbers of platelet transfusions; they also received induction chemotherapy for similar durations and had similar probabilities of progression-free survival and overall survival. Conclusion The addition of EPO to the G-CSF regimen provides no benefit for patients receiving intensive induction chemotherapy for high-risk neuroblastoma.
Phase I Trial of Weekly Docetaxel With Concurrent Three-Dimensional Conformal Radiation Therapy in the Treatment of Unfavorable Localized Adenocarcinoma of the Prostate
Authors: Kumar Parvesh , Perrotti Michael , Weiss Robert , Todd Mary , Goodin Susan , Cummings Kenneth , DiPaola Robert S. 
Published: May 2004

Purpose A phase I trial was conducted to determine the maximally tolerated dose (MTD) of concurrent weekly docetaxel and three-dimensional conformal radiation therapy (3-D CRT) in unfavorable localized adenocarcinoma of the prostate. Patients and Methods Patients with unfavorable localized adenocarcinoma of the prostate underwent daily 3-D CRT to a total dose of 70.2 Gy at 1.8 Gy/fraction and concurrent docetaxel given once a week for 8 to 9 weeks. The initial weekly docetaxel dose level was 5 mg/m2 and the docetaxel doses were escalated as follows: 8, 12, 16, 20, and 25 mg/m2. Results Between January 2000 and August 2002, 22 men completed the chemoradiation therapy protocol. The dose-limiting toxicity was grade 3 diarrhea, which occurred in the first two patients treated at the 25 mg/m2 docetaxel dose level. The MTD of weekly docetaxel was determined to be 20 mg/m2. The overall incidence of grade 2 diarrhea and grade 2 dysuria was 36% and 23%, respectively. Seven (32%) and 15 (68%) patients did not experience any diarrhea or dysuria, respectively. No neutropenia or thrombocytopenia was observed. One patient required intermittent urinary catherization 10 months postcompletion of therapy, which resolved without any surgical intervention. Seventeen patients remain in prostate-specific antigen remission. At a median follow-up interval of 8 months (range, 2 to 27 months), all patients are alive. Conclusion Concurrent weekly docetaxel in conjunction with 3-D CRT is well tolerated with acceptable toxicity. The MTD of weekly docetaxel was determined to be 20 mg/m2 with concurrent 3-D CRT.
International Assessment of the Quality of Clinical Practice Guidelines in Oncology Using the Appraisal of Guidelines and Research and Evaluation Instrument
Authors: Burgers J.S. , Fervers B. , Haugh M. , Brouwers M. , Browman G. , Philip T. , Cluzeau F.A. 
Published: May 2004

Purpose To describe the quality of oncology guidelines developed in different countries. Methods The Appraisal of Guidelines and Research and Evaluation (AGREE) Instrument was used to assess the quality of 100 guidelines (including 32 oncology guidelines) from 13 countries. The criteria of the instrument are grouped into six quality domains: scope and purpose, stakeholder involvement, rigor of development, clarity and presentation, applicability, and editorial independence. Results Oncology guidelines had significantly higher scores on rigor of development than nononcology guidelines (42.2% v 29.4%; P = .02). In particular, systematic methods to search for evidence were more often used (P = .01); the methods for formulating the recommendations were more clearly described (P = .02); and health benefits, risks, and side effects were more often considered in formulating the recommendations (P = .03). Although the standardized scores for the other domains were not significantly different, the oncology guidelines had significantly higher scores for items measuring inclusion of all relevant professional groups (P = .05), consideration of patient views (P = .04), and presentation of different options (P = .05). Only three organizations producing oncology guidelines had standardized scores more than 60% for more than three domains. Conclusion The quality of clinical practice guidelines (CPGs) is modest in general, but for certain domains, oncology guidelines seem to be of better quality than others. The experience of the organization may explain higher scores for some items. Research projects and training aimed at improving the quality of guidelines should be developed. The AGREE instrument could provide a basis for defining steps in a shared development approach to produce high-quality CPGs.