bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrasound of peripheral nerves in acromegaly: changes at 1‐year follow‐up
Authors: Resmini Eugenia , Tagliafico Alberto , Nizzo Raffaella , Bianchi Federico , Minuto Francesco , Derchi Lorenzo , Martinoli Carlo , Ferone Diego 
Published: November 2008

SummaryContext  We have previously demonstrated peripheral nerve enlargement in acromegaly.Objective  The aim of this study was to use ultrasound (US) to assess any changes in the peripheral nerves of patients with acromegaly 1 year after the first evaluation.Patients  We prospectively examined the median and ulnar nerve cross‐sectional area (CSA) in 34 non‐diabetic, patients with acromegaly (18 females and 16 males; 18–79 years) and 34 age‐, sex‐, BMI‐matched controls, using a 17–5 MHz US probe.Intervention  The median nerve was examined at the mid‐forearm (MN‐f) and at the carpal tunnel (MN‐Ct) levels; the ulnar nerve at mid‐forearm (UN‐f) and at distal arm (UN‐a). Patients were grouped according to the clinical control of the disease: ‘improved’; ‘always controlled’; ‘always uncontrolled’; and ‘worsened’.Results  The median nerve at mid‐forearm (MN‐f), the ulnar nerve at mid‐forearm (UN‐f) and at distal arm (UN‐a) were significantly reduced after 1‐year follow‐up in all patients (P < 0·001, P < 0·008, P < 0·012, respectively). In the ‘improved’ group, there was a significant reduction of median nerve CSA examined at mid‐forearm (MN‐f) (P = 0·02), and distal arm ulnar nerve CSA (UN‐a) (P = 0·002). In the other groups no statistically significant differences in ultrasound parameters were recorded. However, UN‐a, UN‐f, MN‐f, MN‐ct were still significantly higher in all groups compared with controls (P < 0·001).Conclusion  These data demonstrate that median and ulnar nerves CSA are reduced after 1 year follow‐up, in line with the reduction of GH/IGF‐I levels. However, as the control of the disease incompletely reverts nerve enlargement, this phenomenon could be only partially reversible.
Organic matter availability structures microbial biomass and activity in a Mediterranean stream
Authors: ARTIGAS JOAN , ROMANÍ ANNA M. , GAUDES AINHOA , MUÑOZ ISABEL , SABATER SERGI 
Published: November 2008

Summary1. We compared microbial biomass (bacteria, fungi, algae) and the activity of extracellular enzymes used in the decomposition of organic matter (OM) among different benthic substrata (leaves, coarse and fine substrata) over one hydrological year in a Mediterranean stream.2. Microbial heterotrophic biomass (bacteria plus fungi) was generally higher than autotrophic biomass (algae), except during short periods of high light availability in the spring and winter. During these periods, sources of OM shifted towards autochthonous sources derived mainly from algae, which was demonstrated by high algal biomass and peptidase activity in benthic communities.3. Heterotrophic activity peaked in the autumn. Bacterial and fungal biomass increased with the decomposition of cellulose and hemicellulose compounds from leaf material. Later, lignin decomposition was stimulated in fine (sand, gravel) and coarse (rocks, boulders and cobbles) substrata by the accumulation of fine detritus.4. The Mediterranean summer drought provoked an earlier leaf fall. The resumption of the water flow caused the weathering of riparian soils and subsequently a large increase in dissolved organic carbon and nitrate, which led to growth of bacteria and fungi.
Use of aniline blue to distinguish live and dead crustacean zooplankton composition in freshwaters
Authors: BICKEL SAMANTHA L. , TANG Kam W. , GROSSART HANS‐PETER 
Published: November 2008

Summary1. Traditional zooplankton sampling methods do not account for the presence of zooplankton carcasses, which could lead to a biased understanding of the ecological role of zooplankton.2. The aniline blue staining method for the differentiation between live and dead freshwater crustacean zooplankton was adapted for field application and the accuracy of the new protocol was tested in the laboratory. Detailed descriptions of the characteristic staining patterns of individuals are provided. The adapted staining method was subsequently applied in a field study to assess the live–dead zooplankton composition in the oligotrophic Lake Stechlin and the eutrophic Lake Dagow in Germany.3. The modified aniline blue staining method accurately identified percentages of mixed live and dead crustacean zooplankton, making it suitable for quantifying live–dead compositions of copepods and cladocerans in freshwater samples.4. On average 6% and 8% of the zooplankton were identified as dead in Lake Stechlin and Lake Dagow, respectively. Within each lake there were no significant spatial variations in the horizontal or vertical distribution of zooplankton carcasses. Nor did the percentage of dead zooplankton differ between day and night.5. The aniline blue staining method provides an effective, simple and economical means for more systematic study of the occurrence and fate of crustacean zooplankton carcasses in freshwaters.
Analysing forest recovery after wildfire disturbance in boreal Siberia using remotely sensed vegetation indices
Authors: CUEVAS‐GONZÁLEZ MARÍA , GERARD FRANCE , BALZTER HEIKO , RIAÑO DAVID 
Published: November 2008

AbstractWildfires have major effects on forest dynamics, succession and the carbon cycle in the boreal biome. They are a significant source of carbon emissions, and current observed changes in wildfire regimes due to changes in climate could affect the balance of the boreal carbon pool. A better understanding of postwildfire vegetation dynamics in boreal forests will help predict the future role of boreal forests as a carbon sink or source. Time series of Normalized Difference Vegetation Index (NDVI) and Normalized Difference Shortwave Infrared Index (NDSWIR) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite were used to investigate whether characteristic temporal patterns exist for stands of different ages in the Siberian boreal forests and whether their postwildfire dynamics are influenced by variables such as prewildfire vegetation cover. Two types of forests, evergreen needle‐leaf (ENF) and deciduous needle‐leaf (DNF), were studied by analysing a sample of 78 burned forest areas. In order to study a longer time frame, a chronosequence of burned areas of different ages was built by coupling information on location and age provided by a forest burned area database (from 1992 to 2003) to MODIS NDVI and NDSWIR time series acquired from 2001 to 2005. For each of the burned areas, an adjacent unburned control plot representing the same forest type was selected, with the aim of separating the interannual variations caused by climate from changes in NDVI and NDSWIR behaviour due to a wildfire. The results suggest that it takes more than 13 years for the temporal NDVI and NDSWIR signal to recover fully after wildfire. NDSWIR, which is associated to canopy moisture, needs a longer recovery period than NDVI, which is associated to vegetation greenness. The results also suggest that variability observed in postwildfire NDVI and NDSWIR can be explained partially by the dominant forest type: while 13 years after a fire NDVI and NDSWIR are similar for ENF and DNF, the initial impact appears to be greater on the NDVI and NDSWIR of ENF, suggesting a faster recovery by ENF.
Carbon dioxide balance of a fen ecosystem in northern Finland under elevated UV‐B radiation
Authors: HAAPALA JAANA K. , MÖRSKY SAMI K. , SAARNIO SANNA , RINNAN RIIKKA , SUOKANERVA HANNE , KYRÖ ESKO , LATOLA KIRSI , MARTIKANEN PERTTI J. , HOLOPAINEN TOINI , SILVOLA JOUKO 
Published: November 2008

AbstractThe effect of elevated UV‐B radiation on CO2 exchange of a natural flark fen was studied in open‐field conditions during 2003–2005. The experimental site was located in Sodankylä in northern Finland (67°22′N, 26°38′E, 179 m a.s.l.). Altogether 30 study plots, each 120 cm × 120 cm in size, were randomly distributed between three treatments (n=10): ambient control, UV‐A control and UV‐B treatment. The UV‐B‐treated plots were exposed to elevated UV‐B radiation level for three growing seasons. The instantaneous net ecosystem CO2 exchange (NEE) and dark respiration (RTOT) were measured during the growing season using a closed chamber method. The wintertime CO2 emissions were estimated using a gradient technique by analyzing the CO2 concentration in the snow pack. In addition to the instantaneous CO2 exchange, the seasonal CO2 balances during the growing seasons were modeled using environmental data measured at the site. In general, the instantaneous NEE at light saturation was slightly higher in the UV‐B treatment compared with the ambient control, but the gross photosynthesis was unaffected by the exposure. The RTOT was significantly lower under elevated UV‐B in the third study year. The modeled seasonal (June–September) CO2 balance varied between the years depending on the ground water level and temperature conditions. During the driest year, the seasonal CO2 balance was negative (net release of CO2) in the ambient control and the UV‐B treatment was CO2 neutral. During the third year, the seasonal CO2 uptake was 43±36 g CO2‐C m−2 in the ambient control and 79±45 g CO2‐C m−2 in the UV‐B treatment. The results suggest that the long‐term exposure to high UV‐B radiation levels may slightly increase the CO2 accumulation to fens resulting from a decrease in microbial activity in peat. However, it is unlikely that the predicted development of the level of UV‐B radiation would significantly affect the CO2 balance of fen ecosystems in future.
Climate change, human land use and future fires in the Amazon
Authors: COCHRANE MARK A. , BARBER CHRISTOPHER P. 
Published: November 2008

AbstractThere is increasing consensus that the global climate will continue to warm over the next century. The biodiversity‐rich Amazon forest is a region of growing concern because many global climate model (GCM) scenarios of climate change forecast reduced precipitation and, in some cases, coupled vegetation models predict dieback of the forest. To date, fires have generally been spatially co‐located with road networks and associated human land use because almost all fires in this region are anthropogenic in origin. Climate change, if severe enough, could alter this situation, potentially changing the fire regime to one of increased fire frequency and severity for vast portions of the Amazon forest. High moisture contents and dense canopies have historically made Amazonian forests extremely resistant to fire spread. Climate will affect the fire situation in the Amazon directly, through changes in temperature and precipitation, and indirectly, through climate‐forced changes in vegetation composition and structure. The frequency of drought will be a prime determinant of both how often forest fires occur and how extensive they become. Fire risk management needs to take into account landscape configuration, land cover types and forest disturbance history as well as climate and weather. Maintaining large blocks of unsettled forest is critical for managing landscape level fire in the Amazon. The Amazon has resisted previous climate changes and should adapt to future climates as well if landscapes can be managed to maintain natural fire regimes in the majority of forest remnants.
Increase in soil organic carbon stock over the last two decades in China's Jiangsu Province
Authors: LIAO QILIN , ZHANG XUHUI , LI ZHIPENG , PAN GENXING , SMITH PETE , JIN YANG , WU XINMIN 
Published: November 2008

AbstractEstimates of regional and national topsoil soil organic carbon (SOC) stock change may help evaluating the soil role in mitigation of greenhouse gas (GHG) emissions through carbon (C) sequestration in soils. However, understanding of the exact mitigation role is often constrained by the uncertainty of the stock estimation associated with different methodologies. In this paper, a soil database of topsoil (0–20 cm) SOC measurements of Jiangsu Province, China, obtained from a soil survey in 1982, and from a geological survey in 2004, was used to analyze the variability of topsoil SOC among soil groups and among soil regions, and to estimate the change in SOC stocks that have occurred in the province over the last two decades. The soil survey data was obtained from measurements of 662 690 randomly collected samples, while the geological survey data was from 24 167 samples taken using a 2 km × 2 km grid. Statistical analysis was conducted on SOC values for 1982 and 2004 for different categories of soil groups, soil regions, and administrative municipalities, respectively. Topsoil SOC storage was then calculated and the provincial topsoil SOC stock was estimated for each sampling time. There were remarkable differences in SOC levels between soil groups and soil regions and different municipalities. The grid sampling with the geological survey in 2004 yielded smaller variability of topsoil SOC averages, both with soil groups and with soil spatial distribution than the random sampling method used in 1982. Variation of SOC was greater with soil groups than with soil regions in both sampling times, although it was less variable across soil taxonomic categories than within a spatial category. Little variance of the SOC level with soil groups could be explained by clay content. However, the prevalence of paddy fields in the total cropland area governed the regional and municipal average SOC levels. The average provincial topsoil SOC content increased from 9.45 g kg−1 in 1982 to 10.9 g kg−1 in 2004, and the total provincial topsoil SOC stock was enhanced from 149.0±58.1 Tg C in 1982 to 173.2±51.4 Tg C in 2004, corresponding to a provincial average SOC sequestration rate of 0.16±0.09 t C ha−1 yr−1. The SOC sequestration trend for the last two decades could be, in part, attributed to the enhanced agricultural production, symbolized by the grain yield per hectare. The results of SOC stock changes suggest a significant C sequestration in soils of Jiangsu, China, during 1980–2000, with paddy management playing an important role in regional SOC storage and sequestration capacity.
Impact of twenty‐first century climate change on diadromous fish spread over Europe, North Africa and the Middle East
Authors: LASSALLE G. , ROCHARD E. 
Published: November 2008

AbstractClimate change is expected to drive species ranges towards the poles and to have a strong influence on species distributions. In this study, we focused on diadromous species that are of economical and ecological importance in the whole of Europe. We investigated the potential distribution of all diadromous fish regularly encountered in Europe, North Africa and the Middle East (28 species) under conditions predicted for twenty‐first century climate change. To do so, we investigated the 1900 distribution of each species in 196 basins spread across all of Europe, North Africa and the Middle East. Four levels were used to semiquantitatively describe the abundance of species, that is missing, rare, common and abundant. We then selected five variables describing the prevailing climate in the basins, the physical nature of the basins and reflecting historical events known to have affected freshwater fish distribution. Logistic regressions with a four‐level ordinal response variable were used to develop species‐specific models. These predictive models related the observed distribution of these species in 1900 to the most explanatory combination of variables. Finally, we selected the A2 SRES scenario and the HadCM3 (Hadley Centre Coupled Model version 3) global climate model (GCM) to obtain climate variables (temperature and precipitation) at the end of this century. We used these 2100 variables in our models and obtained maps of climatically suitable and unsuitable basins, percentages of contraction or expansion for each species. Twenty‐two models were successfully built, that is there were five species for which no model could be established because their distribution range was too narrow and the Acipenser sturio model failed during calibration. All the models selected temperature or/and precipitation as explanatory variables. Responses to climate change were species‐specific but could be classified into three categories: little or no change in the distribution (five species), expansion of the distribution range (three species gaining suitable basins mainly northward) and contraction of the distribution (14 species losing suitable basins). Shifting ranges were in accordance with those found in other studies and underlined the high sensitivity of diadromous fish to modifications in their environment.
Change in CO2 balance under a series of forestry activities in a cool‐temperate mixed forest with dense undergrowth
Authors: TAKAGI KENTARO , FUKUZAWA KARIBU , LIANG NAISHEN , KAYAMA MASAZUMI , NOMURA MUTSUMI , HOJYO HAJIME , SUGATA SADAO , SHIBATA HIDEAKI , FUKAZAWA TATSUYA , TAKAHASHI YOSHIYUKI , NAKAJI TATSURO , OGUMA HIROYUKI , MANO MASAYOSHI , AKIBAYASHI YUKIO , MURAYAMA TAKESHI , KOIKE TAKAYOSHI , SASA KAICHIRO , FUJINUMA YASUMI 
Published: November 2008

AbstractTo evaluate the effects on CO2 exchange of clearcutting a mixed forest and replacing it with a plantation, 4.5 years of continuous eddy covariance measurements of CO2 fluxes and soil respiration measurements were conducted in a conifer‐broadleaf mixed forest in Hokkaido, Japan. The mixed forest was a weak carbon sink (net ecosystem exchange, −44 g C m−2 yr−1), and it became a large carbon source (569 g C m−2 yr−1) after clearcutting. However, the large emission in the harvest year rapidly decreased in the following 2 years (495 and 153 g C m−2 yr−1, respectively) as the gross primary production (GPP) increased, while the total ecosystem respiration (RE) remained relatively stable. The rapid increase in GPP was attributed to an increase in biomass and photosynthetic activity of Sasa dwarf bamboo, an understory species. Soil respiration increased in the 3 years following clearcutting, in the first year mainly owing to the change in the gap ratio of the forest, and in the following years because of increased root respiration by the bamboo. The ratio of soil respiration to RE increased from 44% in the forest to nearly 100% after clearcutting, and aboveground parts of the vegetation contributed little to the RE although the respiration chamber measurements showed heterogeneous soil condition after clearcutting.
Primary production dynamics and climate variability: ecological consequences in semiarid Chile
Authors: DE LA MAZA MARIANO , LIMA MAURICIO , MESERVE PETER L. , GUTIÉRREZ JULIO R. , JAKSIC FABIAN M. 
Published: November 2008

AbstractIncrease in rainfall variability has important consequences for organisms in arid and semiarid regions around the world. In South American and Australian deserts, the El Niño/Southern Oscillation (ENSO) phenomenon greatly influences rainfall patterns, and therefore the dynamics of plant communities. However, the field data needed to assess the effect of climate change on vegetational patterns is difficult to obtain because of the large spatial scale required for such studies. Normalized Difference Vegetation Index (NDVI) characteristics allow the use of several indexes related to vegetational structure. Due to its direct relationship with primary productivity, it is possible to obtain several measures of annual productivity. These include annual plant yield, annual maximum yield, onset of ‘greening‐up’ and senescence phases, length of the ‘green’ season, vegetation peak, and therefore, the periods when more or less food is available for herbivores. After verification with ground‐truth measures, we used NDVI data from two semiarid localities in north‐central Chile (Fray Jorge and Aucó) to determine the relationship between rainfall patterns and vegetation cover and productivity related to El Niño phenomenon. With this information we gauge the influence of climatic processes on primary productivity in western South America, an area subject to strong climate variability. We predict significant variation in Chilean semiarid regions due to climate change, affecting mainly the extent and timing of annual growth season of vegetation, and also including a shorter and delayed greening‐up season. Also, we predict that important decreases in rainfall levels will not have strong effects on primary production in these semiarid ecosystems.
Impacts of an anomalously warm year on soil nitrogen availability in experimentally manipulated intact tallgrass prairie ecosystems
Authors: VERBURG PAUL S. J. , JOHNSON DALE W. , SCHORRAN DAVID E. , WALLACE LINDA L. , LUO Y. , ARNONE III JOHN A. 
Published: November 2008

AbstractGlobal climate change can potentially increase the frequency of climate anomalies. Anomalously warm years may cause an increase in soil nitrogen (N) availability by stimulating N mineralization. To date, most studies addressing the effects of ecosystem warming have been conducted in relatively cold ecosystems and few studies have addressed impacts of interannual as opposed to continuous, multiyear warming. In this study, 12 intact soil monoliths were excavated from a tallgrass prairie site near Purcell, Oklahoma, USA and divided among four large flux chambers (EcoCELLs). During the first year, all four EcoCELLs were subjected to Oklahoma air temperatures and precipitation. During the second year, air temperature in two EcoCELLs was increased by 4 °C throughout the year resulting in an increase in soil temperature of 2.3 °C at 7.5 cm depth. During the third and fourth years, temperatures in the warmed EcoCELL returned back to ‘normal’ conditions. During the warming year, vegetation N content was not significantly affected by the warming treatment suggesting no change in N availability. Other N availability indicators (soil solution chemistry, leaching, and N adsorption by ion exchange resins) did not show any effect of warming. Soil solution, leaching, and ion exchange resins showed a large pulse of NH4+at the start of the study most likely due to disturbance caused by monolith excavation and transport but these effects were short‐lived and had disappeared before the treatment started. The lack of a clear warming effect may be explained by a reduction in soil moisture in the warming treatments compared with the controls offsetting a potential stimulation of N mineralization in response to increased temperatures. As a result, effects of an anomalously warm year on N availability in warmer ecosystems may be small compared with colder ecosystems but are likely to depend on soil moisture status.