bluuebunny/crossref_metadata_2025_split huggingface dataset:
Markers of eosinophilic inflammation and risk prediction in patients with coronary artery disease
Authors: Falcone C. , Minoretti P. , D’Angelo A. , Buzzi M. P. , Coen E. , Emanuele E. , Aldeghi A. , Olivieri V. , Geroldi D. 
Published: March 2006

AbstractBackground  The eotaxin family comprises three distinct peptides (eotaxin, eotaxin‐2 and eotaxin‐3) which have been implicated in eosinophilic inflammation. In vitro and clinical studies suggest that eotaxins could play a role in vascular inflammation, but no data are available on their prognostic significance in patients with angiographically documented coronary artery disease (CAD).Materials and methods  Baseline plasma samples were obtained from 1014 patients with documented CAD. We tested the predictive effect of markers of eosinophilic inflammation and C‐reactive protein (CRP) on death from cardiovascular causes and nonfatal myocardial infarction over a 2·7–4·1‐year follow‐up period.Results  Unexpectedly, lower eotaxin‐3 concentrations were observed in patients with adverse cardiovascular events, whereas both eotaxin and eotaxin‐2 showed no association with risk. After adjustment for most potential confounders, patients in the upper‐quartile of eotaxin‐3 levels had a 0·42 hazard‐ratio (95% CI, 0·29–0·61, P < 0·001) for adverse events compared with subjects in the lower‐quartile. The highest risk of future cardiovascular events was observed in subjects with combined elevation of CRP and reduction of eotaxin‐3; 4·4 hazard‐ratio (95% CI, 2·1–9·5, P < 0·001). Importantly, receiver‐operating‐characteristic curves analysis suggested a superior prognostic value of eotaxin‐3 compared with CRP for predicting cardiac events in patients with CAD.Conclusions  Low levels of eotaxin‐3 are an independent predictor of future adverse cardiovascular events in patients with CAD and may be useful for risk stratification.
T‐lymphocyte subset distribution in human spleen
Authors: Langeveld M. , Gamadia L. E. , Ten Berge I. J. M. 
Published: March 2006

AbstractBackground  When analyzing human cellular immune responses, most focus is placed on the peripheral blood (PB) and, to a lesser extent, the lymph nodes. To date the spleen has not been analyzed with regard to its role in adaptive cellular immunity and more notably not with respect to T‐cell immune responses.Materials and methods  We analyzed the splenic lymphocyte compartment in comparison with the PB lymphocyte compartment regarding the number of NK cells, B cells, CD4+, CD8+ T cells and CMV‐specific CD8+ T cells. Furthermore, we analyzed the distribution of naive, memory and effector subsets of CD4+ and CD8+ T cells in these compartments.Results  The spleen contains proportionally more B cells and less CD4+ and CD8+ T cells than PB. The percentage of CD8+ T cells is greater in the spleen, leading to an inverse CD4/CD8 ratio. Both splenic CD4+ and CD8+ T‐cell populations show a greater number of activated cells, and splenic CD8+ T cells show a more differentiated cytotoxic CD27−CD45RA+ memory phenotype.Conclusions  Our findings show that the distribution of the different lymphocyte subsets is markedly different between the spleen and the PB, thus inferring an important and distinct role for the spleen in CD4+ and CD8+ T‐cell activation.
Land‐use history and fire effects on soil fertility in eastern Spain
Authors: Duguy B. , Rovira P. , Vallejo R. 
Published: March 2006

SummaryChanges in land use and fire directly affect the physico‐chemical properties of the soil. In an eastern Spanish area, we analysed the effects of land‐use history and fire frequency prior to fire on soil fertility 9 years after fire. The results showed that long‐term cultivation caused decreases in soil organic matter, total nitrogen (N) and C/N. Between 20 and 40 years after cropping ceased, soil organic carbon (C) and total N had generally not recovered values similar to those found in soils that were never cropped. Total phosphorus and available phosphorus contents were larger in the latest abandoned plots than in the earliest abandoned plots and the uncropped ones, which was interpreted as a result of fertilization. Increasing fire frequency from one to two fires generally caused a decrease in soil organic C, total N, C/N, total phosphorus and available phosphorus. We observed that the losses of organic C in the soil caused by fire were larger among the uncropped plots and hypothesized that fuel loads and thus fire intensities were larger in these ecosystems. Our results also suggested that both long‐term cultivation and fire would tend to separate C and P cycles.
Aggregate‐occluded black carbon in soil
Authors: Brodowski S. , John B. , Flessa H. , Amelung W. 
Published: March 2006

SummaryThe great stability of black carbon (BC) in soils may not be solely attributable to its refractory structure but also to poor accessibility when physically enveloped by soil particles. Our aim was to elucidate the intensity of physical entrapment of BC within soil aggregates. For this purpose, the A horizon of a forest, and of a grassland soil, and of three soils under tillage, were sampled at the experimental station Rotthalmünster, Germany. Black carbon was assessed in water‐stable aggregates and aggregate‐density fractions using benzene polycarboxylic acids as specific markers. The greatest BC concentrations made up 7.2% of organic carbon and were found in the < 53 μm fraction. The smallest BC concentrations occurred in the large macroaggregate fractions (> 2 mm). This pattern has been sustained even after tillage. The C‐normalized BC concentrations were significantly greater (P < 0.05) in the occluded particulate organic matter (OPOM) fractions than in the free particulate organic matter (FPOM) and the mineral fractions. This enrichment of BC compared with organic carbon in the OPOM fractions amounted to factors of 1.5–2.7. Hence, BC was embedded within microaggregates in preference to other organic carbon compounds. Only 2.5–3.5% of BC was located in the OPOM fraction < 1.6 g cm−3, but 22–24% in the OPOM fraction with a density of 1.6–2.0 g cm−3. This suggests that BC possibly acted as a binding agent or was selectively enriched during decomposition of protected SOM, or both. Physical inclusion, particularly within microaggregates, could therefore contribute to the long mean‐residence times of soil‐inherent BC.
The use of periphytic diatoms as a means of assessing impacts of point source inorganic nutrient pollution in south‐eastern Australia
Authors: DELA‐CRUZ JOCELYN , PRITCHARD TIM , GORDON GEOFFREY , AJANI PENELOPE 
Published: March 2006

Summary1. Periphytic diatoms are used as indicators of water quality because their ecological tolerances or preferences to environmental variables are thought to be predictable. However, much of the present autecological information for periphytic diatoms has been derived from studies conducted in the northern hemisphere. In this present study we used periphytic diatoms to determine the impacts of inorganic nutrient pollution in a tidal river system in the temperate latitudes of south‐east Australia. In so doing, we assess the suitability of the use of the ‘northern hemisphere’ ecological tolerance/preference data for periphytic diatoms.2. Artificial substrates were used to collect periphytic diatoms at 35 sites, which were positioned along the riverbanks and the middle of the river at various distances upstream and downstream of the sewage outfall. The sampling design took into account tidal excursions and the observed sewage plume dynamics. Periphytic diatoms were collected during the austral winter month of August and the austral spring months of September and October. We deployed the artificial substrates for 4 weeks to allow the periphytic diatoms to recruit and colonise, before identifying and enumerating the assemblages.3. Data analysis included two approaches: multivariate visualisations of combinations of environmental and biological data to investigate shifts in species structure of the periphytic diatom assemblage and multimetric indices based on ecological tolerance/preference data.4. We found that the spatial patterns inferred from multivariate and multimetric analyses were consistent. Temporal variation in the composition of the periphytic diatom assemblage was greater than the spatial variation along horizontal sections of the river (in any one deployment) due mainly to shifts between winter and spring species.5. Outfall effects were most apparent in winter, possibly because subsequent deployments were swamped by growth of spring periphytic diatoms. The outfall effects included a shift towards pollutant tolerant species and a reduction in the variability of the periphytic diatom assemblage across the river.6. We conclude that the use of periphytic diatoms and associated ecological tolerance/preference data as a means of assessing impacts of point source inorganic nutrient pollution is effective. An understanding of river and sewage flow patterns is essential to the design of appropriate monitoring programmes and to the interpretation of results, especially as periphytic diatoms are sensitive to many environmental variables.
Combining meteorology, eddy fluxes, isotope measurements, and modeling to understand environmental controls of carbon isotope discrimination at the canopy scale
Authors: ARANIBAR J. N. , BERRY J. A. , RILEY W. J. , PATAKI D. E. , LAW B. E. , EHLERINGER J. R. 
Published: March 2006

AbstractEstimates of terrestrial carbon isotope discrimination are useful to quantify the terrestrial carbon sink. Carbon isotope discrimination by terrestrial ecosystems may vary on seasonal and interannual time frames, because it is affected by processes (e.g. photosynthesis, stomatal conductance, and respiration) that respond to variable environmental conditions (e.g. air humidity, temperature, light). In this study, we report simulations of the temporal variability of canopy‐scale C3 photosynthetic carbon isotope discrimination obtained with an ecophysiologically based model (ISOLSM) designed for inclusion in global models. ISOLSM was driven by half‐hourly meteorology, and parameterized with eddy covariance measurements of carbon and energy fluxes and foliar carbon isotope ratios from a pine forest in Metolius (OR). Comparing simulated carbon and energy fluxes with observations provided a range of parameter values that optimized the simulated fluxes. We found that the sensitivity of photosynthetic carbon isotope discrimination to the slope of the stomatal conductance equation (m, Ball–Berry constant) provided an additional constraint to the model, reducing the wide parameter space obtained from the fluxes alone. We selected values of m that resulted in similar simulated long‐term discrimination as foliar isotope ratios measured at the site. The model was tested with 13C measurements of ecosystem (δR) and foliar (δf) respiration. The daily variability of simulated 13C values of assimilated carbon (δA) was similar to that of observed δf, and higher than that of observed and simulated δR. We also found similar relationships between environmental factors (i.e. vapor pressure deficit) and simulated δR as measured in ecosystem surveys of δR. Therefore, ISOLSM reasonably simulated the short‐term variability of δA controlled by atmospheric conditions at the canopy scale, which can be useful to estimate the variability of terrestrial isotope discrimination. Our study also shows that including the capacity to simulate carbon isotope discrimination, together with simple ecosystem isotope measurements, can provide a useful constraint to land surface and carbon balance models.
Iron limits primary productivity during spring bloom development in the central North Atlantic
Authors: MOORE C. MARK , MILLS MATTHEW M. , MILNE ANGELA , LANGLOIS REBECCA , ACHTERBERG ERIC P. , LOCHTE KARIN , GEIDER RICHARD J. , LA ROCHE JULIE 
Published: March 2006

AbstractWe present in situ biophysical measurements and bioassay experiments that demonstrate iron limitation of primary productivity during the spring bloom in the central North Atlantic. Mass balance calculations indicate that nitrate drawdown is iron (Fe)‐limited and that aeolian Fe supply to this region cannot support maximal phytoplankton growth during the bloom. Using a simple simulation model, we show that relief of Fe limitation during the spring bloom can increase nitrate drawdown and, hence, new primary production, by 70%. We conclude that the episodic nature of iron supplied by dust deposition is an important factor controlling the dynamics of the spring bloom. From this, we hypothesize that variability in the timing and magnitude of the spring bloom in response to aeolian Fe supply will affect carbon drawdown and food web dynamics in the central North Atlantic.
Estimating the uncertainty in annual net ecosystem carbon exchange: spatial variation in turbulent fluxes and sampling errors in eddy‐covariance measurements
Authors: OREN RAM , HSIEH CHENG‐I , STOY PAUL , ALBERTSON JOHN , MCCARTHY HEATHER R , HARRELL PETER , KATUL GABRIEL G 
Published: March 2006

AbstractAbove forest canopies, eddy covariance (EC) measurements of mass (CO2, H2O vapor) and energy exchange, assumed to represent ecosystem fluxes, are commonly made at one point in the roughness sublayer (RSL). A spatial variability experiment, in which EC measurements were made from six towers within the RSL in a uniform pine plantation, quantified large and dynamic spatial variation in fluxes. The spatial coefficient of variation (CV) of the scalar fluxes decreased with increasing integration time, stabilizing at a minimum that was independent of further lengthening the averaging period (hereafter a ‘stable minimum’). For all three fluxes, the stable minimum (CV=9–11%) was reached at averaging times (τp) of 6–7 h during daytime, but higher stable minima (CV=46–158%) were reached at longer τp (>12 h) during nighttime. To the extent that decreasing CV of EC fluxes reflects reduction in micrometeorological sampling errors, half of the observed variability at τp=30 min is attributed to sampling errors. The remaining half (indicated by the stable minimum CV) is attributed to underlying variability in ecosystem structural properties, as determined by leaf area index, and perhaps associated ecosystem activity attributes. We further assessed the spatial variability estimates in the context of uncertainty in annual net ecosystem exchange (NEE). First, we adjusted annual NEE values obtained at our long‐term observation tower to account for the difference between this tower and the mean of all towers from this experiment; this increased NEE by up to 55 g C m−2 yr−1. Second, we combined uncertainty from gap filling and instrument error with uncertainty because of spatial variability, producing an estimate of variability in annual NEE ranging from 79 to 127 g C m−2 yr−1. This analysis demonstrated that even in such a uniform pine plantation, in some years spatial variability can contribute ∼50% of the uncertainty in annual NEE estimates.
Impacts of climate change on natural forest productivity – evidence since the middle of the 20th century
Authors: BOISVENUE CÉLINE , RUNNING STEVEN W. 
Published: March 2006

AbstractChanges to forest production drivers (light, water, temperature, and site nutrient) over the last 55 years have been documented in peer‐reviewed literature. The main objective of this paper is to review documented evidence of the impacts of climate change trends on forest productivity since the middle of the 20th century. We first present a concise overview of the climate controls of forest production, provide evidence of how the main controls have changed in the last 55 years, followed by a core section outlining our findings of observed and documented impacts on forest productivity and a brief discussion of the complications of interpreting trends in net primary production (NPP). At finer spatial scales, a trend is difficult to decipher, but globally, based on both satellite and ground‐based data, climatic changes seemed to have a generally positive impact on forest productivity when water was not limiting. Of the 49 papers reporting forest production levels we reviewed, 37 showed a positive growth trend, five a negative trend, three reported both a positive and a negative trend for different time periods, one reported a positive and no trend for different geographic areas, and two reported no trend. Forests occupy ≈52% of the Earth's land surface and tend to occupy more temperature and radiation‐limited environments. Less than 7% of forests are in strongly water‐limited systems. The combined and interacting effects of temperature, radiation, and precipitation changes with the positive effect of CO2, the negative effects of O3 and other pollutants, and the presently positive effects of N will not be elucidated with experimental manipulation of one or a few factors at a time. Assessments of the greening of the biosphere depend on both accurate measurements of rates (net ecosystem exchange, NPP), how much is stored at the ecosystem level (net ecosystem production) and quantification of disturbances rates on final net biome production.
Climatic signals in growth and its relation to ENSO events of two Prosopis species following a latitudinal gradient in South America
Authors: LÓPEZ BERNAT C. , RODRÍGUEZ RODOLFO , GRACIA CARLOS A. , SABATÉ SANTIAGO 
Published: March 2006

AbstractSemiarid environments throughout the world have lost a major part of their woody vegetation and biodiversity due to the effects of wood cutting, cattle grazing and subsistence agriculture. The resulting state is typically used for cattle production, but the productivity of these systems is often very low, and erosion of the unprotected soil is a common problem. Such dry‐land degradation is of great international concern, not only because the resulting state is hardly productive but also because it paves the way to desertification. The natural distribution of the genus Prosopis includes arid and semiarid zones of the Americas, Africa and Asia, but the majority of the Prosopis species are, however, native to the Americas. In order to assess a likely gradient in the response of tree species to precipitation, temperature and their connection to El Niño southern oscillation (ENSO) events, two Prosopis species were chosen along a latitudinal gradient in Latin America, from northern Peru to central Chile: Prosopis pallida from a semi‐arid land in northern and southern Peru and P. chilensis from a semiarid land in central Chile. Growth rings of each species were crossdated at each sampling site using classical dendrochronological techniques. Chronologies were related with instrumental climatic records in each site, as well as with SOI and N34 series. Cross‐correlation, spectral and wavelet analysis techniques were used to assess the relation of growth with precipitation and temperature. Despite the long distance among sites, the two Prosopis species presented similar responses. Thus, the two species' growth is positively correlated to precipitation, while with temperature it is not. In northern Peru, precipitation and growth of P. pallida present a similar cyclic pattern, with a period of around 3 years. On the other hand, P. pallida in southern Peru, and P. chilensis also present this cyclic pattern, but also another one with lower frequency, coinciding with the pattern of precipitation. Both cycles are within the range of the ENSO band.
A UK‐based investigation of inter‐ and intra‐observer reproducibility of Gleason grading of prostatic biopsies
Authors: Melia J , Moseley R , Ball R Y , Griffiths D F R , Grigor K , Harnden P , Jarmulowicz M , McWilliam L J , Montironi R , Waller M , Moss S , Parkinson M C 
Published: March 2006

Aims:  The frequency of prostatic core biopsies to detect cancer has been increasing with more widespread prostate specific antigen (PSA) testing. Gleason score has important implications for patient management but morphological reproducibility data for British practice are limited. Using literature‐based criteria nine uropathologists took part in a reproducibility study.Methods:  Each of the nine participants submitted slides from consecutive cases of biopsy‐diagnosed cancer assigned to the Gleason score groups 2–4, 5–6, 7 and 8–10 in the original report. A random selection of slides was taken within each group and examined by all pathologists, who were blind to the original score. Over six circulations, new slides were mixed with previously read slides, resulting in a total of 47 of 81 slides being read more than once.Results:  For the first readings of the 81 slides, the agreement with the consensus score was 78% and overall interobserver agreement was κ 0.54 for Gleason score groups 2–4, 5–6, 7, 8–10. Kappa values for each category were 0.33, 0.56, 0.44 and 0.68, respectively. For the 47 slides read more than once, intra‐observer agreement was 77%, κ 0.66. The study identified problems in core biopsy interpretation of Gleason score at levels 2–4 and 7. Patterns illustrated by Gleason as 2 tended to be categorized as 3 because of the variable acinar size and unassessable lesional margin. In slides with consensus Gleason score 7, 13% of readings were scored 6 and in slides with consensus 6, 18% of readings were scored 7.Conclusions:  Recommendations include the need to increase objectivity of the Gleason criteria but limits of descriptive morphology may have to be accepted.
Interstitial fibrosis in the heart: differences in extracellular matrix proteins and matrix metalloproteinases in end‐stage dilated, ischaemic and valvular cardiomyopathy
Authors: Herpel E , Pritsch M , Koch A , Dengler T J , Schirmacher P , Schnabel Ph A 
Published: March 2006

Aims:  To investigate whether or not there are differences in the distribution of extracellular matrix (ECM) proteins and matrix metalloproteinases (MMPs) in end‐stage heart failure underlying different cardiomyopathies.Methods and results:  Thirty‐nine explanted human hearts were investigated: 15 with dilated cardiomyopathy (DCM), 17 with ischaemic cardiomyopathy (ICM) and seven with valvular cardiomyopathy (VCM). Transmural samples from four different sites were investigated. Frozen sections were processed for immunohistochemistry for collagens type I, III, IV, laminin and fibronectin, as well as MMP‐1, ‐2 and ‐9. Volume densities were determined. All ECM components were expressed more frequently in DCM than in ICM. Comparing ICM with VCM, all proteins were found more frequently in VCM than in ICM except for type III collagen, which was significantly more frequent in ICM. Comparing DCM and VCM, VCM showed significantly higher volume densities for type III collagen and laminin. MMPs showed only slight variations between the cardiomyopathies.Conclusion:  The distribution of ECM proteins differs between DCM, ICM and VCM, which suggests that they can be morphologically discriminated by interstitial fibrosis, especially by their expression of matrix proteins.