bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of fibrogenic/fibrolytic genes by platelet‐derived growth factor C, a novel growth factor, in human dermal fibroblasts
Authors: Jinnin Masatoshi , Ihn Hironobu , Mimura Yoshihiro , Asano Yoshihide , Yamane Kenichi , Tamaki Kunihiko 
Published: August 2004

AbstractPlatelet‐derived growth factor (PDGF) is a potent mitogenic and chemotactic cytokine, and PDGF‐C is a novel growth factor belonging to the PDGF family. In this study, to determine whether this growth factor can contribute to fibrosis and tissue remodeling, we examined the effect of PDGF‐CC on the expression of fibrogenic/fibrolytic genes such as type I collagen, fibronectin (FN), matrix metalloproteinases (MMPs), and their inhibitors (TIMPs) in normal human dermal fibroblasts in vitro. PDGF elevated the levels of MMP‐1 or TIMP‐1 protein as well as mRNA, whereas this cytokine had no influence on the expression of type I collagen, FN, or TIMP‐2. PDGF‐CC also increased the levels of MMP‐1 catalytic activity in the cultured media and mRNA expression, which was paralleled that on the levels of promoter activation. Additionally, PDGF‐CC induced the mitogenic and migratory activity of human dermal fibroblasts in a dose‐dependent manner. On the other hand, we also determined the specificity of the inhibitory effect of monoclonal antibodies against PDGF‐CC generated by immunizing balb/c mice with recombinant human PDGF‐CC. This antibody could inhibit the regulatory effects of MMP‐1 or TIMP‐1 synthesis as well as the mitogenic effects on human dermal fibroblasts induced by PDGF‐CC, whereas this antibody did not affect those induced by other PDGF forms such as PDGF‐AA, ‐AB, or ‐BB. These results suggest that this cytokine plays a role in the tissue remodeling. © 2004 Wiley‐Liss, Inc.
The use of nutshell carbons in drinking water filters for removal of chlorination by‐products
Authors: Ahmedna Mohamed , Marshall Wayne E , Husseiny Abdo A , Goktepe Ipek , Rao Ramu M 
Published: August 2004

AbstractChlorination of drinking water is a common practice, used by numerous municipalities in the United States (US) to safeguard their water supplies. However, the chlorine used can chemically react with organic components in the drinking water to produce unwanted chlorination by‐products. The objective of this investigation was to evaluate the use of granular activated carbon produced from nutshells (almond, English walnut, pecan) in a point‐of‐use (POU) water filtration system designated ‘Envirofilter’ and to determine its efficacy in removing select, potentially carcinogenic chlorination by‐products, namely the trihalomethanes (THMs) bromodichloromethane, bromoform and dibromochloromethane. The POU water filtration system that contained the nutshell‐based carbons was designated ‘Envirofilter’ and adsorption efficiencies of this system were compared to that of four commercially available POU home water filter systems, namely, BRITA, Omni Filter, PŪR and Teledyne Water Pik. Eight different ‘Envirofilters’ were constructed of individual or binary mixtures of carbons produced from acid‐activated almond or pecan shells and steam‐activated pecan or walnut shells and evaluated for adsorption of the three chlorination by‐products. The results indicate that only two of the eight ‘Envirofilters’ failed to remove more THMs than the commercial POU systems. In both cases, these filters contained carbons with either 100% acid‐activated almond shells or 100% acid‐activated pecan shells. All six of the other filters contained carbons with either 50% or 100% steam‐activated pecan shells or steam‐activated walnut shells. Therefore, ‘Envirofilters’ appeared to depend on the presence of steam‐activated nutshell carbons for their success. The six effective ‘Envirofilters’ reduced THM levels to below the Maximum Contaminant Levels (MCL) required by the US Environmental Protection Agency (US EPA). Based on these results, these six ‘Envirofilters’ may be considered as a replacement for existing commercial filter systems because of their efficacy and projected cost. Copyright © 2004 Society of Chemical Industry
Protective effect of green tea polyphenol EGCG against neuronal damage and brain edema after unilateral cerebral ischemia in gerbils
Authors: Lee Hyung , Bae Jae Hoon , Lee Seong‐Ryong 
Published: August 2004

AbstractPrevious studies have demonstrated that a green tea polyphenol, (−)‐epigallocatechine gallate (EGCG), has a potent free radical scavenging and antioxidant effect. Glutamate leads to excitotoxicity and oxidative stress, which are important pathophysiologic responses to cerebral ischemia resulting in brain edema and neuronal damage. We investigated the effect of EGCG on excitotoxic neuronal damage in a culture system and the effect on brain edema formation and lesion after unilateral cerebral ischemia in gerbils. In vitro, excitotoxicity was induced by 24‐hr incubation with N‐methyl‐D‐aspartate (NMDA; 10 μM), AMPA (10 μM), or kainate (20 μM). EGCG (5 μM) was added to the culture media alone or with excitotoxins. We examined malondialdehyde (MDA) level and neuronal viability to evaluate the effect of EGCG. In vivo, unilateral cerebral ischemia was induced by occlusion of the right common carotid artery for 30, 60, or 90 min and followed by reperfusion of 24 hr. Brain edema, MDA, and infarction were examined to evaluate the protective effect of EGCG. EGCG (25 or 50 mg/kg, intraperitoneally) was administered twice, at 30 min before and immediately after ischemia. EGCG reduced excitotoxin‐induced MDA production and neuronal damage in the culture system. In the in vivo study, treatment of gerbils with the lower EGCG dose failed to show neuroprotective effects; however, the higher EGCG dose attenuated the increase in MDA level caused by cerebral ischemia. EGCG also reduced the formation of postischemic brain edema and infarct volume. These results demonstrate EGCG may have future possibilities as a neuroprotective agent against excitotoxicity‐related neurologic disorders such as brain ischemia. © 2004 Wiley‐Liss, Inc.
Nitrogen mineralization from mature bio‐waste compost in vineyard soils. I. Long‐term laboratory incubation experiments
Authors: Nendel Claas , Reuter Stephan , Kubiak Roland , Nieder Rolf 
Published: August 2004

AbstractThe steadily increasing utilization of bio‐waste compost in German viticulture requires a more detailed investigation of nitrogen (N) mineralization parameters for mature bio‐waste compost applied to vineyard soils. N mineralization kinetics were described with two superposing exponential equations. Long‐term aerobic laboratory incubation experiments of 12 soil‐compost substrates revealed that 5±2.8% of its total N content could be released from a rapidly decomposable fraction (half‐life period t50 = 41 d at 15°C) and another 60±2.9% from a slower decomposable fraction (t50 = 490 d). The remaining proportion (35%) is considered not to be released in the medium term. The obtained potentially mineralizable nitrogen of 65% of total compost N significantly differs from current fertilizer recommendations, which were adopted from calculations for agricultural conditions. For fertilizer recommendations in viticulture, we recommend the consideration of a higher N‐mineralization potential for organic fertilizers.
The influence of phosphorus nutrition on the physiological response of moth bean genotypes to drought
Authors: Garg Balvinder K. , Burman Uday , Kathju Shyam 
Published: August 2004

AbstractFour genotypes of moth bean (Vigna aconitifolia Jacq. Marechal), including two early (RMO‐257 and CZM‐18) and two late flowering types (CAZRI moth‐1 and Jawala) were grown at two levels of phosphorus (0 and 40 kg ha–1) and subjected to drought by withholding of water until wilting at the pre‐flowering stage in a pot trial. Drought significantly decreased plant water potential, relative water content, rate of net photosynthesis, contents of chlorophyll, starch, soluble protein, and nitrate reductase activity in all genotypes. The adverse effects of drought were less pronounced in early than in late flowering genotypes. Phosphorus application significantly ameliorated the negative effects of drought on above parameters, particularly in the late genotypes. We conclude that P addition to moth bean may be justified even in low‐rainfall years because of its ability to improve yield under water‐limited conditions.
Compositional nutrient diagnosis and main nutrient interactions in yellow pepper grown on desert calcareous soils
Authors: García‐Hernández José Luis , David Valdez‐Cepeda Ricardo , Murillo‐Amador Bernardo , Nieto‐Garibay Alejandra , Beltrán‐Morales Luis Felipe , Magallanes‐Quintanar Rafael , Troyo‐Diéguez Enrique 
Published: August 2004

AbstractMineral‐nutrient stress is one of the main factors limiting crop production, especially in arid lands. The mineral requirement of a crop is difficult to determine, and the interpretation of foliar chemistry composition is not easy. This study was conducted to compute the minimum yield target for fresh fruit of yellow pepper (Capsicum annuum L.) and the corresponding Compositional Nutrient Diagnosis (CND) as well as to identify significant nutrient interactions of this crop in desert calcareous soils. Preliminary CND norms were developed using a cumulative variance‐ratio function and the chi‐square distribution function. From a small database, we computed means and standard deviations of row‐centered log ratios, VX, of five nutrients (N, P, K, Ca, and Mg) and a filling value, R, which comprises all nutrients not chemically analyzed and quantified them in 54 foliar samples of the popular yellow pepper cv. ‘Santa Fé’. This cultivar is widely grown in northwest Mexico under arid conditions. These norms are associated to fresh fruit yields higher than 15.04 t ha–1. Principal‐component analyses, performed using estimated CND nutrient indexes, allowed us to identify four interactions: negative P‐Ca, P‐Mg, and N‐K, and positive Ca‐Mg. Pepper plants growing on calcareous soils tend to take up more Ca and Mg than considered as optimum in other soil conditions.
Effect of defoliation on patterns of carbon exudation from Agrostis capillaris
Authors: Murray Philip , Ostle Nicholas , Kenny Carolyn , Grant Helen 
Published: August 2004

AbstractGrassland ecosystems are important global sinks and sources of atmospheric carbon (C). In this study, we used an in‐situ 13CO2 tracer approach to quantify differences in short‐term C exudation from defoliated and non‐defoliated Agrostis capillaris (L.) plants subjected to natural diurnal light and temperature regimes and rainfall events. Results showed: 1. There was no significant difference in overall carbon exudation from the plants as a result of defoliation; 2. defoliation significantly increased exudation of recent photosynthate (i.e., 13C labeled); 3. there was a distinct and statistically significant diurnal trend in C exudation with root C exudation increasing during the day and early evening and decreasing during the night and early morning. The importance of light/temperature and defoliation as drivers of patterns of root C exudation and the contribution of recent assimilate C to atmosphere‐plant‐soil carbon flow are discussed.
Development and practical test of a weighable groundwater lysimeter for floodplain sites
Authors: Bethge‐Steffens Doerthe , Meissner Ralph , Rupp Holger 
Published: August 2004

AbstractPresently, the soil water balance of flood‐influenced soils in fluvial plains is insufficiently described. The new development of a weighable groundwater lysimeter is the basis for recording the water‐balance components precipitation, evapotranspiration, groundwater recharge, capillary rise, and interaction with the water course. Soil‐hydrologic measuring setups at two floodplain sites of the Elbe river serve for direct comparability of lysimeter measurements with data obtained on site. A groundwater control was designed for lysimeters that automatically adjusts the current groundwater level at the floodplain measuring setups and quantifies inflow into or outflow from the lysimeter. It turned out that the lysimeter developed is capable of identifying the individual water‐balance quantities at high accuracy. Contrary to previous assumptions, it was possible to prove groundwater recharge for the floodplain sites.
Ist der Konzentrationsfaktor k eines aggregierten Bodens als steuernde Größe der mechanischen Druckverteilung in Böden eine Konstante?
Authors: Becher Hans Heinrich 
Published: August 2004

AbstractDie Mechanisierung in der Land‐ und Forstwirtschaft hat u. a. zu einer erheblichen Zunahme der Gewichte der im Gelände eingesetzten Maschinen und Geräte geführt. Letztere überschreiten zumindest in voll beladenem Zustand mit etwa 60 t (Zuckerrübenroder) deutlich das zulässige Gewicht von 40 t für Fahrzeuge im Straßenverkehr. Die durch diese oder ähnlich hohe Auflasten verursachte Bodenverdichtung steht im Widerspruch zu den Zielen des Bundesbodenschutzgesetzes. Deshalb ist die Beschäftigung mit der Druckfortpflanzung in tiefe Bodenschichten notwendig. Anhand einiger Beispiele wird gezeigt, dass der Konzentrationsfaktor k, der die Druckfortpflanzung steuert, sich unter dem Einfluss von Natur (Bodengenese, Wassergehalt) und/oder Menschen (Bodenbearbeitung, Ernte) sowohl räumlich als auch zeitlich ändert. Diese nicht vermeidbare Variabilität erschwert die Abschätzung der theoretischen Reichweite einer Bodenverdichtung anhand nur weniger Messwerte. Denn selbst während der Passage eines Gespanns ändern sich die Bedingungen für die Bodenverdichtung. Folglich ist der Konzentrationsfaktor k keine Bodenkonstante.
Experimental determination of climate‐change effects on above‐ground and below‐ground organic matter in alpine grasslands by translocation of soil cores
Authors: Egli Markus , Hitz Christian , Fitze Peter , Mirabella Aldo 
Published: August 2004

AbstractWe used the soil‐core translocation method to investigate the effect of increased temperature on above‐ and below‐ground phytomass and organic matter in cool alpine areas. The translocation of undisturbed soil cores from a high alpine site (2525 m a.s.l.) to an alpine site near the timberline (1895 m a.s.l.) achieved an effective artificial warming of 3.3 K. From a methodological point of view, the translocation of soil cores was performed successfully. Soil cores moved to a new site at the same altitude showed no change in above‐ and below‐ground vegetation, bulk density, and soil skeleton. At both sites, soils were Haplic Podzols with a similar chemistry and clay mineralogy. At the lower elevation site, however, podzolization processes seemed to be more pronounced. As a consequence, the translocation of the soil cores probably led to a disturbance of the actual steady state that had been established after about 10,000–13,000 years of soil formation. This might have affected the adaptability of the vegetation system. Therefore, it cannot be fully excluded that the experimental design influenced the results. Translocation of soil cores from a very cool to a warmer site led to a distinct decrease in above‐ground phytomass (about –45%) over the experimental period of two years. Below‐ground phytomass significantly decreased (up to –50%) in the topsoil (0–5 cm) after artificial warming. Possible mechanisms are that roots reduced photosynthesis and hence C flow below‐ground, a reduction of soil moisture that would have led to root death (not a very probable cause, however) or an abrupt change in the radiation duration and flux which affected root growth (also not very probable). Fast climate change exceeded the ability of the above‐ground and below‐ground phytomass to adapt quickly. Whether the decrease in phytomass was a short‐term or a long‐term response to climate warming remains uncertain. Based on a gradient study (climosequence at the same locality), we hypothesize that the decreased plant productivity might be a short‐term effect.
Temperature functions of the rate coefficients of net N mineralization in sandy arable soils. Part I. Derivation from laboratory incubations
Authors: Heumann Sabine , Böttcher Jürgen 
Published: August 2004

AbstractThis study aimed to experimentally determine adequate temperature functions for the rate coefficients of net N mineralization in sandy arable soils from NW Germany. Long‐term laboratory incubations were carried out in seven sandy arable soils at 3°C, 10°C, 19°C, 28°C, and 35°C in order to derive the rate coefficients of a simultaneous two‐pool first‐order kinetic equation. Thereby we differentiated between a small, fast mineralizable N pool, comprising mainly fresh residues, and a larger, slowly mineralizable N pool of old, humified organic matter. The rate coefficients were plotted against temperature, and fits of several different functions were tested: Arrhenius, Q10, and multiple non‐mechanistic equations. The two derived rate coefficients showed very different temperature functions. Especially in critical temperature ranges (<5/10°C, >30/35°C) common Q10 functions failed to fit well, and, only below 10°C, the Arrhenius functions were in agreement with mean measured rate coefficients. Over the studied temperature range, only relatively complex, multiple equations could adequately account for the observed patterns. In addition, temperature functions that have been derived earlier from loess soils from NW Germany were found not to be transferable to the sandy arable soils studied. Thus, the results strongly question the use of the same Arrhenius or Q10 function or the same rate modifying factor for different N pools as well as for different soils as is generally done in models. Evaluations with field measurements of net N mineralization in part II of the paper (Heumann and Böttcher, 2004) will show which functions perform best in the field.
Cation exchange properties of soils derived from lignite ashes
Authors: Zikeli Sabine , Kastler Michael , Jahn Reinhold 
Published: August 2004

AbstractIn Saxony‐Anhalt, Germany, an area of about 6000 ha is covered by lignite‐ash‐derived substrates. In some cases, pollutants like heavy metals or toxic organic compounds had been disposed of together with the lignite ashes. For this reason, we assessed factors influencing the cation exchange capacity (CEC) of lignite‐ash substrates exposed to natural weathering.We chose four research sites reflecting the different methods of disposal: two dumped landfills and two lagooned ashes of different ages. After determining the CEC at pH 8.1 (CECpot), we evaluated the influence of the content of silt and clay and the content of total organic C. As lignite‐ash‐derived substrates are rich in oxalate‐extractable Si, Al, and Fe, we performed an oxalate extraction and determined afterwards the CECpot to assess the contribution of oxalate‐soluble compounds to the CECpot. Moreover, we determined the variable charge of selected samples at pH values ranging from 4 to 7.The lignite‐ash‐derived soils had a high CECpot with means ranging from 25.1 cmolc kg–1 to 88.8 cmolc kg–1. The influence of the parent material was more important than the degree of weathering. The content of total organic C consisting of pedogenic organic matter and coked lignite particles together with the content of silt and clay played a statistically significant role in determining the CEC.Another property that influenced the amount of CEC in medium textured lignite ashes was the content of oxalate‐soluble silica and aluminum. After oxalate extraction, they lost about 30% of their CEC due to the dissolution of oxalate‐soluble compounds. In coarse textured lignite ashes, oxalate extraction led to higher amounts of CEC, probably due to an increase of surface area resulting either from the disintegration of particles or from etching caused by insufficient dissolution of magnetite and maghemite. Moreover, lignite‐ash‐derived substrates exhibit a high amount of pH‐dependent charge. The CEC decreased by 40% in a topsoil sample and by 51% in a subsoil sample as the pH declined from 7 to 4.
Microbial biomass and respiration in soils derived from lignite ashes: a profile study
Authors: Machulla Galina , Zikeli Sabine , Kastler Michael , Jahn Reinhold 
Published: August 2004

AbstractMicrobial biomass C and soil respiration measurements were made in 17–20 yr old soils developed on sluiced and tipped coal‐combustion ashes. Topsoil (0–30 cm) and subsoil (30–100 cm) samples were collected from three soil profiles at two abandoned disposal sites located in the city area of Halle, Saxony‐Anhalt. Selected soil physical (bulk density and texture) and chemical (pH, organic C, total N, CEC, plant available K and P, and total Cd and Cu) properties were measured. pH values were significantly lower while organic C and total N contents and the C : N ratio were significantly higher in the topsoil than in the subsoil indicating the effects of substrate weathering and pedogenic C accumulation. Likewise, microbial biomass C, K2SO4‐extractable C, and soil respiration with median values of 786 μg biomass C g–1, 262 μg K2SO4‐C g–1, and 6.05 μg CO2‐C g–1 h–1, respectively, were significantly higher in the topsoil than in the subsoil. However, no significant difference was observed in metabolic quotient between the topsoil and the subsoil. Metabolic quotient with median values of 5.98 and 8.54 mg CO2‐C (g biomass C)–1 h–1 for the 0–30 cm and 30–100 cm depths, respectively, was higher than the data reported in the literature for arable and forest soils. Microbial biomass C correlated significantly with extractable C but no relationship was observed between it and total N, Cd, and Cu contents, as well as plant‐available K and P. We conclude that the presence of the remarkable concentration of extractable C in the weathered lignite ashes allowed the establishment of microbial populations with high biomass. The high metabolic quotients observed might be attributed to the heavy‐metal contamination and to the microbial communities specific to ash soils.
Adding dissolved organic carbon to simulate freeze‐thaw related N2O emissions from soil
Authors: Sehy Ulrike , Dyckmans Jens , Ruser Reiner , Munch Jean Charles 
Published: August 2004

AbstractIt has been assumed that high winter N2O emissions from soils are the result of increased amounts of microbially available organic C liberated during freezing and metabolized during subsequent thawing. In a laboratory experiment, we attempted to simulate freeze‐thaw events by adding dissolved organic C (DOC) to sieved soil of high water content (95% water‐filled pore space). In a full factorial design, CO2 and N2O emissions of a) soil samples provided with DOC extracted from frozen soil and b) soil samples frozen for 46 days and thawed were compared. Additionally, NO$_3^-$, DOC and microbial ATP contents of all treatments were repeatedly analyzed during the experiment.The addition of DOC to unfrozen soil (–F+C) resulted in a substantial (22‐fold) increase in N2O emissions as compared to the control (–F–C). However, following thawing, the increase in N2O emissions was much larger (828‐fold in +F–C and 1243‐fold in +F+C). Freezing, but not the addition of DOC led to increased CO2 emissions. Neither treatment affected microbial adenylate content. By adding 15N‐labeled nitrate to the soil samples, the main process leading to elevated N2O flux rates after both DOC addition and freeze‐thaw treatment was identified as denitrification.We conclude that the availability of C substrate plays an important role for freeze‐thaw‐related N2O emissions. However, the fact that the simulated treatment and the freeze‐thaw treatment yielded significantly different amounts of N2O suggests that both quantity and quality of available C differed between the treatments. The localization of the liberated substrate, i.e., the availability in situ, seems to be of major importance for the amount of N2O produced.