bluuebunny/crossref_metadata_2025_split huggingface dataset:
Net ecosystem CO2 exchange measured by autochambers during the snow‐covered season at a temperate peatland
Authors: Bubier Jill , Crill Patrick , Mosedale Andrew 
Published: December 2002

AbstractNet ecosystem exchange of CO2 was measured at a temperate peatland in southeastern New Hampshire. Classified as a mineral‐poor fen owing to deep, water‐logged peats that are influenced to a limited extent by groundwater, the ecosystem is dominated by plants such as sedges (Carex spp.) and evergreen shrubs. Ten automatic chambers measured fluxes every 3 h by sampling changes in headspace concentration of CO2 from November 2000 through March 2001. The fen was covered in snow for most of this period and CO2 was emitted from the snow pack throughout the winter. The largest fluxes were associated with ground temperatures of 0°C and with declining atmospheric pressure. CO2 effluxes up to 3 µmol m−2 s−1 were recorded when the ground temperature reached the thaw point. Fluxes were lower when the ground temperature rose above 0°C, however, suggesting that the large fluxes were associated with a build up and release of stored CO2 degassing as soon as the ground thawed, or by enhanced microbial activity associated with freeze–thaw dynamics. The large number of thaw events coupled with frequent short‐term releases of CO2 suggest that degassing occurred on a regular basis with changes in atmospheric pressure and/or microbial decomposition occurred beneath the snowpack. The extent of soil freezing prior to thaw was also an important factor, with colder soils yielding smaller CO2 emissions upon thaw. Although most of the observed CO2 flux was efflux from the ecosystem, occasional CO2 uptake by the ecosystem of up to 1 µmol m−2 s−1 was also observed, indicating small rates of photosynthesis even during winter. Photosynthesis occurred only when the ground temperature was >0°C. The implications for a warmer climate are unclear. If warmer winter temperatures yield less snow in the temperate region, then soils could freeze more deeply and result in lower CO2 emissions. However, if less snow results in a higher frequency of freeze–thaw events, then winter CO2 emissions could be larger with a warmer climate. Copyright © 2002 John Wiley & Sons, Ltd.
Interannual variations in snowpack in the Crown of the Continent Ecosystem
Authors: Selkowitz David J. , Fagre Daniel B. , Reardon Blase A. 
Published: December 2002

AbstractEcosystem changes such as glacier recession and alpine treeline advance have been documented over the previous 150 years in the Rocky Mountains of northern Montana and southern British Columbia and Alberta, a region known as the Crown of the Continent Ecosystem (CCE). Such changes are controlled, at least partially, by variations in snowpack. The CCE consists primarily of public lands, the majority of which is undeveloped or wilderness. Consequently, this region is well suited for an examination of long‐term snowpack variation and associated ecosystem change. Data from nine SNOTEL sites provide an indication of the daily accumulation and ablation of snowpack over the period 1977–2001, as well as the relationship between precipitation, temperature and snowpack. 1 April data from 21 snow courses indicated the extent of regional snowpack variation and trends over the period 1950–2001, and 1 May data from three snow courses in Glacier National Park allow this record to be extended back to 1922. SNOTEL data suggest CCE snowpacks are larger and more persistent than in most regions of the western USA, and that water year precipitation is the primary control on 1 April snow water equivalent (SWE). Snow course data indicate that variations in both 1 April and 1 May mean SWE are closely tied to the Pacific decadal oscillation, an El Niño–southern oscillation‐like interdecadal pattern of Pacific Ocean climate variability. Despite relatively stable snowpacks and summer temperatures since 1922, the glaciers in Glacier National Park have receded steadily during this period, implying a significant climatic shift between their Little Ice Age glacial maxima (ca 1860) and 1922. Published in 2002 by John Wiley & Sons Ltd.
Cytokine, chemokine, and matrix metalloproteinase response after sulfur mustard injury to weanling pig skin
Authors: Sabourin Carol L. K. , Danne Michele M. , Buxton Kristi L. , Casillas Robert P. , Schlager John J. 
Published: December 2002

AbstractCutaneous exposure to sulfur mustard [bis(2‐chloroethyl) sulfide; SM] produces a delayed inflammatory skin response and severe tissue injury. Pig skin has organ similarities to human skin that is characterized by the content and types of epidermal lipids, the density of hair follicles and presence of sweat glands, which together afford penetration of topically applied compounds, complex inflammatory responses, and subsequent wound healing. The goal of this study was to identify in vivo proinflammatory biomarkers of the SM porcine skin injury within 72 h after SM challenge, using the weanling pig model. Changes in gene expression of inflammatory mediators were examined at 3, 6, 24, 48, and 72 h, using subtraction library analyses and by quantitation of selected transcripts by reverse transcription–polymerase chain reaction (RT–PCR). Sequence analysis of subtraction libraries identified up‐regulation of IL‐8 at 24, 48, and 72 h. No other specific proinflammatory gene transcripts were isolated from the libraries. Specific transcript RT–PCR analysis showed increased production of interleukin‐1β (IL‐1β), interleukin‐6 (IL‐6), interleukin‐8 (IL‐8), and matrix metalloproteinase‐9 (MMP‐9, gelatinase B) mRNA levels in response to SM exposure. Tumor necrosis factor‐α (TNF‐α) expression was only slightly increased and no change in the levels of expression was observed for monocyte chemoattractant protein‐1 and MMP‐2. This study identifies the main proinflammatory mediators involved in SM‐induced skin injury in a weanling pig model. The results suggest transcriptional activity in the inflammatory response proteins IL‐8, IL‐6, IL‐1β, and MMP‐9 and modest changes in TNF‐α that together produce inflammation and contribute to the pathogenesis of SM dermatotoxicity. Therefore, drugs preventing SM‐induced inflammation should be prime candidates for medical intervention to lessen collateral inflammation associated with tissue destruction. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:263–272, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10050
The roles of cytochrome b5 in cytochrome P450 reactions
Authors: Porter Todd D. 
Published: December 2002

AbstractCytochrome b5, a 17‐kDa hemeprotein associated primarily with the endoplasmic reticulum of eukaryotic cells, has long been known to augment some cytochrome P450 monooxygenase reactions, but the mechanism of stimulation has remained controversial. Studies in recent years have clarified this issue by delineating three pathways by which cytochrome b5 augments P450 reactions: direct electron transfer of both required electrons from NADH–cytochrome b5 reductase to P450, in a pathway separate and independent of NADPH–cytochrome P450 reductase; transfer of the second electron to oxyferrous P450 from either cytochrome b5 reductase or cytochrome P450 reductase; and allosteric stimulation of P450 without electron transfer. Evidence now indicates that each of these pathways is likely to operate in vivo. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:311–316, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10052
Use of [125I]4′‐iodoflavone as a tool to characterize ligand‐dependent differences in Ah receptor behavior
Authors: Swanson Hollie I. , Whitelaw Murray L. , Petrulis John R. , Perdew Gary H. 
Published: December 2002

AbstractWe have synthesized [125I]4′‐iodoflavone to study Ah receptor (AhR)–ligand interactions by a class of AhR ligands distinct from the prototypic ligand 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD). This radioligand allows the comparison of AhR–ligand interactions using a ligand that differs in AhR affinity, and yet has the same radiospecific activity as [125I]2‐iodo‐7,8‐dibromodibenzo‐p‐dioxin. Specific binding of [125I]4′‐iodoflavone with the AhR was detected as a single radioactive peak (∼9.7 S) following density sucrose gradient analysis. Cytosolic extracts from both Hepa 1 and HeLa cells were used as the source of mouse and human AhR, respectively. A ∼6.7 S form of radioligand‐bound Ah receptor was detected in the high salt nuclear extracts of both cell lines. In HeLa cells approximately twofold more [125I]4′‐iodoflavone–AhR 6 S complex, compared with [125I]2‐iodo‐7,8‐dibromodibenzo‐p‐dioxin, was recovered in nuclear extracts. A comparison of the ability of 4′‐iodoflavone and TCDD to cause time‐dependent translocation of AhR‐yellow fluorescent protein revealed that 4′‐iodoflavone was more efficient at enhancing nuclear accumulation of the receptor. These results suggest that [125I]4′‐iodoflavone is a particularly useful and easily synthesized ligand for studying the AhR. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:298–310, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10053
Biochemical characteristics of purified beef liver NADPH–cytochrome P450 reductase
Authors: Arinç Emel , Ļelik Haydar 
Published: December 2002

AbstractNADPH–cytochrome P450 reductase, an obligatory component of the cytochrome P450 dependent monooxygenase system, was purified to electrophoretic homogeneity from beef liver microsomes. The purification procedure involved the ion exchange chromatography of the detergent‐solubilized microsomes on first and second DEAE‐cellulose columns, followed by 2′,5′‐ADP Sepharose affinity chromatography. Further concentration of the enzyme and removal of Emulgen 913 and 2′‐AMP were accomplished on the final hydroxylapatite column. The enzyme was purified 239‐fold and the yield was 13.5%. Monomer molecular weight of the enzyme was estimated to be 76000 ± 3000 (N = 5) by SDS‐PAGE. The absolute absorption spectrum of beef reductase showed two peaks at 455 and 378 nm, with a shoulder at 478 nm, characteristics of flavoproteins. The effects of cytochrome c concentration, pH, and ionic strength on enzyme activity were studied. Reduction of cytochrome c with the enzyme followed Michaelis–Menten kinetics, and the apparent Km of the purified enzyme was found to be 47.7 μM for cytochrome c when the enzyme activity was measured in 0.3 M potassium phosphate buffer (pH 7.7). Stability of cytochrome c reductase activity was examined at 25 and 37°C in the presence and absence of 20% glycerol. The presence of glycerol enhanced the stability of cytochrome c reductase activity at both temperatures. Sheep lung microsomal cytochrome P4502B and NADPH–cytochrome P450 reductase were also purified by the already existing methods developed in our laboratory. Both beef liver and sheep lung reductases were found to be effective in supporting benzphetamine and cocaine N‐demethylation reactions in the reconstituted systems containing purified sheep lung cytochrome P4502B and synthetic lipid, phosphatidylcholine dilauroyl. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:286–297, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10054
Business ideologies and perceived breach of contract during downsizing: the role of the ideology of employee self‐reliance
Authors: Edwards John C. , Rust Kathleen G. , McKinley William , Moon Gyewan 
Published: December 2002

AbstractThis paper represents an initial effort to explore the empirical relationship between business ideologies and perceptions of organizational downsizing. The results of four studies, two conducted in the US and one each in Singapore and Korea, suggest that respondents' belief in the ideology of employee self‐reliance reduces the degree to which they perceive layoffs as a breach of the psychological contract. This finding appears to generalize to respondents' perceptions of their own layoffs and also to respondents' perceptions of layoffs happening to others. We spell out the implications of these results for the evolving theory of the ideological foundations of perceptions of downsizing. Copyright © 2003 John Wiley & Sons, Ltd.
An electrochemical investigation into the galvanic corrosion of carbon steel coupled to carbon fibres
Authors: Bozzini B. , Fanigliulo A. 
Published: December 2002

AbstractThe problem of galvanic coupling of mild steel to carbon fibres in aqueous solutions relevant to environmental exposure cases is attacked in this research. Acid sulphate and near neutral chloride and bicarbonate solutions are considered. The application background of this investigation is the mechanical joining of carbon‐fibre reinforced polymer‐matrix composites. This research is based on the following electrochemical measurements: galvanic current, corrosion potential, linear‐sweep voltammetry, electrochemical impedance spectroscopy and time‐dependent impedance. The combination of electrochemical measurements performed directly on the galvanically coupled system and on the single materials exposed to the environments of interest, gives insight into the kinetic and mechanistic factors leading to a given, time dependent behaviour of the galvanic couple. Time drifts of the corrosion performance of the couple were assessed and passivation or localised corrosion phenomena highlighted.
Zum Korrosionsverhalten von Nicrofer 3033 in hochkonzentrierter Schwefelsäure
Authors: Werner H. , Riedel G. , Brill U. 
Published: December 2002

AbstractUntersuchungen zum Korrosionsverhalten von Nicrofer 3033 (1.4591) erfolgten in 93%iger und 95–99%iger technischer Schwefelsäure bei Temperaturen von 70–200°C. 6‐h‐Versuche mit gravimetrischer Auswertung und Messung des Freien Korrosionspotentials und 48‐h‐Versuche mit gravimetrischer Auswertung dienten zur Ermittlung des Einflusses von Schwefelsäurekonzentration und Temperatur bei An‐ und Abwesenheit von SO2 auf die Beständigkeit von Blechproben. Der Einfluss der Strömungsgeschwindigkeit wurde in 6‐h‐Versuchen durch Rotation von Rohrproben bei Umfangsgeschwindigkeiten bis 2 m/s untersucht.Aus den Potential‐ und gravimetrischen Messungen folgt für Temperaturen ab 100°C eine Beständigkeit mit ≤ 0,1 mm/a für Nicrofer 3033 (1.4591) ab etwa 98,5%. Um 125°C scheint jedoch ein Gebiet zu existieren, wo zumindest bei längerer Versuchsdauer die Beständigkeit bis herab zu etwa 97,5% erhalten bleibt. Untersuchungen zum Strömungseinfluss weisen darauf hin, dass in dem genannten Gebiet mit zunehmender Strömungsgeschwindigkeit wieder eine Aktivierung erfolgt. Bei den anderen Temperaturen ist dagegen der Strömungseinfluss gering.Diese Ausweitung des Beständigkeitsbereiches um 125°C belegt, dass die Temperaturabhängigkeit von Nicrofer 3033 (1.4591) in hochkonzentrierter Schwefelsäure nicht monoton ist. Es treten in Abhängigkeit von der Schwefelsäurekonzentration bei unterschiedlichen Temperaturen Korrosionsmaxima und ‐minima auf. Bei Anwesenheit von SO2 erfolgt nur bei niedrigen Versuchstemperaturen, 80°C, 100°C im 6‐h‐Versuch und 70°C, 80°C im 48‐h‐Versuch, eine Einengung des Beständigkeitsbereiches.
The stainless steel screw as an orthopaedic implant
Authors: Rozman J. , Kmetič M. , Bunc M. , Pihlar B. 
Published: December 2002

AbstractThe study reported here dealt with the metallographical inspection and analysis of corrosion behavior of screws for mild Slipped Capital Femoral Epiphysis (SCFE), which is a serious orthopedical problem in early adolescence. The screws were fabricated from low carbon, austenitic grade stainless steel type 316L (AISI) with 1600 ppm of nitrogen (316LN2). They were clinically tested in a nearly 25‐year‐long study where patients in early adolescence were operated with these screws with the fixation in situ. Since the results obtained in all patients were similar, we present the results obtained in screws removed after 3 years of implantation from a 14‐year‐old boy. Metallographical inspection results reveal that a low content of carbon in the SS 316LN2, and annealing this material at a high temperature ensures the monophasic microstructure of austenitic grains. In the grains twin bands that appeared during mechanical deformation were observed. As the hardness measured at the stalk (262 HV) was lower than that measured at the head of the screw (293 HV) it was concluded that cold mechanical deformation of the head was much more extensive than that of the stalk. Accordingly, corrosion of the head could be more probable than that of the stalk. Corrosion behavior of the screw in simulated physiological media (0.9% NaCl solution), carried out by the electrochemical method, gave an Ecorr of −0.124 V (vs. SCE), corrosion current density of 21 nA/cm2, and corrosion rate of 0.010 ± 0.005 mpy. This low corrosion rate indicates that SS 316LN2 expresses relatively high corrosion resistance in a saline solution. However, potentiodynamic polarization measurements, where the specimen was driven to more than 1.8 V above the Ecorr., showed that in the region between −0.1 and 0.15 V the specimen corroded, while around 0.2 V a small valley appeared where passivation proceeded. The narrow passive region between 0.15 and 0.25 V indicated that chlorides prevented the formation of thick protecting films. With potentials more positive than 0.3 V the passivating film broke down and the specimen began to corrode. These data indicate that SS 316LN2 can not be effectively protected by passivation since it is not corrosion resistant in a chloride containing environment.
Soy isoflavonoid equol modulates the growth of benign and malignant prostatic epithelial cells in vitro
Authors: Hedlund Tammy E. , Johannes Widya U. , Miller Gary J. 
Published: December 2002

AbstractBACKGROUNDThe dietary consumption of high levels of soy has been linked to reduced risks for prostate cancer (PC) in Asians and vegetarians. In vitro studies have focused on the two most abundant isoflavones in soy, genistein and daidzein. However, daidzein is differentially metabolized by gut microflora in humans, yielding compounds with very different bioactivities and half‐lives. Asians are significantly more likely to produce the metabolite equol than Caucasians, suggesting its role in the prevention of PC. We hypothesize that equol is a bioactive metabolite that exerts direct antiproliferative effects on prostatic epithelial cells.METHODSBenign and malignant prostatic epithelial cells were treated in vitro with equol, genistein, and daidzein by using the range of concentrations found in the prostatic fluids of Asians consuming soy. Growth and cell cycle distribution were analyzed over time.RESULTSAfter 9 days of treatment, equol inhibited growth of benign human prostatic epithelial cells (PrEC) by 37% at 10−6 M and 80% at 10−5 M. Although genistein also had profound effects, daidzein appeared only one tenth as potent as equol. Equol and daidzein caused an accumulation of cells in G0/G1, whereas genistein arrested cells in G2/M. The isoflavonoids demonstrated differential effects on the established PC cell lines 22Rv1, LNCaP, LAPC‐4, PC‐3, and DU 145. PC‐3 cells showed the greatest resistance.CONCLUSIONEquol is a biologically active metabolite of daidzein that has potent antiproliferative effects on benign and malignant prostatic epithelial cells at concentrations that can be obtained naturally through dietary soy consumption. Prostate 54: 68–78, 2003. © 2002 Wiley‐Liss, Inc.
Differential expression of specific FGF ligand and receptor isoforms during angiogenesis associated with prostate cancer progression
Authors: Huss Wendy J. , Barrios Roberto J. , Foster Barbara A. , Greenberg Norman M. 
Published: December 2002

AbstractBACKGROUNDThe aim of this study was to elucidate how changes in temporal and spatial expression patterns of individual components of the fibroblast growth factor (FGF) signaling axis correlate with prostate cancer‐associated angiogenesis to contribute to the progression of this disease.METHODSThe temporal and spatial expression patterns of specific FGF ligands and receptors were characterized by immunoblot, in situ hybridization, and immunohistochemical analyses in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model.RESULTSWe detected expression of high molecular weight isoform of FGF‐2 in PIN lesions and detected both high and low molecular weight isoforms of FGF‐2 in advanced tumors. Expression of the mRNA encoding the FGFR1iiib isoform was found to be specifically and differentially expressed in tumor vasculature in TRAMP but was not detected in prostate‐associated vasculature in nontransgenic mice. Expression of the FGFR2iiic isoform was observed to be elevated in the epithelial component of PIN lesions in TRAMP mice.CONCLUSIONBy using the TRAMP model, the expression of FGFR1iiib in intraductal vasculature and expression of FGF‐2 protein were found to be concomitant with the emergence of PIN. These observations implicate specific changes in the FGF axis with the initiation and progression of prostate cancer and underscore the utility of animal models to identify specific molecular changes in early disease. Prostate 54: 8–16, 2003. © 2002 Wiley‐Liss, Inc.
Inhibition of the enzymatic activity of prostate‐specific antigen by boric acid and 3‐nitrophenyl boronic acid
Authors: Gallardo‐Williams Maria T. , Maronpot Robert R. , Wine Robert N. , Brunssen Susan H. , Chapin Robert E. 
Published: December 2002

AbstractBACKGROUNDProstate specific antigen (PSA) is a well‐established marker of prostate cancer, but it can also degrade extracellular matrix proteins such as fibronectin and could be involved in tumor progression and metastasis. In this study, we have addressed the use of boric acid and 3‐nitrophenyl boronic acid (NPBA) as PSA inhibitors in vitro.METHODSThe inhibition of PSA by boric acid was studied by using specific fluorogenic substrates. Fibronectin, a biologically relevant substrate for PSA, was used as a substrate in a zymographic assay, and the degradation of fibronectin by PSA in the presence of boric acid and NPBA was followed by Western Blot.RESULTSLow concentrations of boric acid partially inhibited the proteolytic activity of PSA toward a synthetic fluorogenic substrate. Also, by Western blot, we have found significant inhibition in the proteolysis of fibronectin by PSA in the presence of boric acid as well as NPBA. Results indicate that the boronated compounds used in this study can be used for the modulation of PSA activity.CONCLUSIONPSA activity is inhibited in vitro by boric acid and NPBA. If degradation of fibronectin by PSA were, in fact, an important step in the progression of prostate cancer, then borate‐induced inhibition of PSA activity should help reduce the development and proliferation of prostate carcinomas. Prostate 54: 44–49, 2003. © 2002 Wiley‐Liss, Inc.
Will succession planning increase shareholder wealth? evidence from investor reactions to relay CEO successions
Authors: Shen Wei , Cannella, Albert A. 
Published: December 2002

AbstractOur study examines investor reactions to a specific form of succession planning—relay succession. Theory predicts that both the initiation and the outcome of a relay CEO succession process will influence shareholder wealth. Our results show that investors generally do not react to the initiation of the process as indicated by heir apparent appointment; but react negatively when the process ends in heir apparent exit from the firm and react positively when the process ends in heir apparent promotion to the CEO position. We also found a strong positive investor reaction to outside CEO promotion and a negative investor reaction to nonheir inside CEO promotion. Further, firm performance exerts an important influence on the wealth effect of heir apparent promotion and exit. Copyright © 2002 John Wiley & Sons, Ltd.