bluuebunny/crossref_metadata_2025 huggingface dataset:
Generalization between receptive and expressive language in young children with autism
Authors: Wynn Jacqueline W. , Smith Tristram
Published: October 2003

Generalization between expressive and receptive language was studied in six boys with autism (chronological age 47–76 months, language age 13–42 months). Each participant received training on three or four word pairs (e.g. hot/cold). Half the pairs were taught expressively and then receptively; the other half were taught in the reverse order. Data were obtained on generalization from the trained to untrained modality, generalization errors, and between‐ and within‐subject differences. Across participants, the ‘expressive first’ condition led to cross‐modal generalization more often than the ‘receptive first’ condition. However, one child displayed the opposite pattern, and three other children's patterns varied across training stimuli. Error analyses indicated that, when children failed to demonstrate receptive‐to‐expressive generalization, they did generalize in another manner: responding based on physical resemblance between cues used in the study and those used in previous training. The results suggest ways to individualize instruction and better understand cross‐modal generalization. Copyright © 2003 John Wiley & Sons, Ltd.
A comparison of differential reinforcement and noncontingent reinforcement for the treatment of a child's multiply controlled problem behavior
Authors: Kodak Tiffany , Miltenberger Raymond G. , Romaniuk Cathryn
Published: October 2003

Noncontingent reinforcement (NCR) and differential reinforcement of other behavior (DRO) with escape as the reinforcer were evaluated after an initial functional analysis indicated the problem behaviors exhibited by a 7 year old child were maintained by escape. When NCR and DRO did not decrease the problem behaviors, a second functional analysis was conducted and showed that the behaviors were maintained by attention and escape. DRO with attention and escape as reinforcers was compared to NCR with attention and escape as reinforcers for the treatment of the child's multiply controlled behavior problems. Results showed that DRO and NCR were both effective at reducing the problem behavior to low levels and increasing compliance. Copyright © 2003 John Wiley & Sons, Ltd.
The effects of three stimulus‐equivalence testing conditions on emergent US geography relations of children diagnosed with autism
Authors: LeBlanc Linda A. , Miguel Caio F. , Cummings Anne R. , Goldsmith Tina R. , Carr James E.
Published: October 2003

Two children with autism were trained in US geography using a match to sample procedure. Different testing procedures commonly used in stimulus equivalence research were compared, including some conditions with reinforcement for responding to enhance motivation. Both children were able to master the trained geography relations and emergent stimulus relations were also noted. All three testing procedures produced similar effects, suggesting that incorporation of procedures to enhance motivation to respond does not invalidate testing in a stimulus equivalence preparation. Copyright © 2003 John Wiley & Sons, Ltd.
Use of ATP bioluminescence to determine the bacterial sensitivity threshold to a bacteriocin
Authors: Valat Charlotte , Champiat Dominique , N'Guyen Thi Thanh Thuy , Loiseau Gérard , Raimbault Maurice , Montet Didier
Published: October 2003

A new ATP bioluminescence‐based method was developed to determine the effectiveness of nisin on a sensitive strain of Lactococcus cremoris. The principle of the method is to quantify the release of adenylic‐nucleotides (AN) by a sensitive strain under the action of the bacteriocin, with the complex luciferin–luciferase. Nisin‐induced leakage of AN included ATP from a sensitive L. cremoris to the external medium immediately after the contact with the bacteria. The growth of L. cremoris was correlated with the extracellular AN content. The extracellular ATP and AN concentration exhibited a linear correlation to the logarithm of the nisin concentration. For the determination of the effectiveness threshold, the concentration of AN was more sensitive and more reliable than the direct quantiﬁcation of ATP. The effectiveness threshold, corresponding to a 100% inhibition of L. cremoris growth, was obtained for a null concentration of intracellular nucleotides, i.e. for a ANtot:ANext ratio = 1. For an initial concentration of 1.4 × 107 bacteria/mL, the nisin effectiveness threshold is 3.4 ± 0.01 mg nisin/L. It is possible to detect effectiveness threshold concentration by taking into account the physiological state of the cells. Copyright © 2003 John Wiley & Sons, Ltd.
Kinetic simulation studies on the transient formation of the oxo‐iron(IV) porphyrin radical cation during the reaction of iron(III) tetrakis‐5,10,15,20‐(N‐methyl‐4‐pyridyl)‐porphyrin with hydrogen peroxide in aqueous solution
Authors: Saha Tapan Kumar , Karmaker Subarna , Tamagake Keietsu
Published: October 2003

High‐valent oxo‐iron(IV) species are commonly proposed as the key intermediates in the catalytic mechanisms of iron enzymes. Water‐soluble iron(III) tetrakis‐5,10,15,20‐(N‐methyl‐4‐pyridyl)porphyrin (Fe(III)TMPyP) has been used as a model of heme‐enzyme to catalyse the hydrogen peroxide (H2O2) oxidation of various organic compounds. However, the mechanism of the reaction of Fe(III)TMPyP with H2O2 has not been fully established. In this study, we have explored the kinetic simulation of the reaction of Fe(III)TMPyP with H2O2 and of the catalytic reactivity of FeTMPyP in the luminescent peroxidation of luminol. According to the mechanism that has been established in this work, Fe(III)TMPyP is oxidized by H2O2 to produce (TMPyP)·+Fe(IV)=O (k1 = 4.5 × 104/mol/L/s) as a precursor of TMPyPFe(IV)=O. The intermediate, (TMPyP)·+Fe(IV)=O, represented nearly 2% of Fe(III)TMPyP but it does not accumulate in sufﬁcient concentration to be detected because its decay rate is too fast. Kinetic simulations showed that the proposed scheme is capable of reproducing the observed time courses of FeTMPyP in various oxidation states and the decay proﬁles of the luminol chemiluminescence. It also shows that (TMPyP)·+Fe(IV)=O is 100 times more reactive than TMPyPFe(IV)=O in most of the reactions. These two species are responsible for the initial sharp and the sustained luminol emissions, respectively. Copyright © 2003 John Wiley & Sons, Ltd.
Validation of different chemilumigenic substrates for detecting extracellular generation of reactive oxygen species by phagocytes and endothelial cells
Authors: Kopprasch Stefﬁ , Pietzsch Jens , Graessler Juergen
Published: October 2003

Chemiluminescence is a widely used tool to detect extracellular generation of reactive oxygen species (ROS). In the present study we tested four different chemilumigenic substrates (CLS)—luminol, isoluminol, lucigenin and pholasin—to detect extracellular CL in different cell types: polymorphonuclear leukocytes (PMN); DMSO‐differentiated HL‐60 cells; murine macrophages (RAW 264.7); and TNFα‐stimulated human endothelial cells (HUVEC). Extracellular ROS production was calculated by subtracting intracellular CL response in the presence of superoxide dismutase and catalase from the overall CL response in the absence of enzymes. CL varied considerably in dependence on the CLS and the stimulus used to evoke ROS generation. Luminol (oxidized LDL and zymosan stimulation) and isoluminol (FMLP and PMA stimulation) were the most effective CLS for PMN. Using 5 µmol/L lucigenin as CLS, small but consistent CL responses could be obtained in macrophages stimulated with PMA, zymosan or oxidized LDL. FMLP‐stimulated extracellular CL in H‐60 cells, HUVEC and macrophages was detected with the greatest sensitivity by pholasin. Our results demonstrate that none of the investigated CLS consistently yielded the highest CL quantum, either in different cell types with one stimulating agent or by different stimulating agents in one cell type. To get the highest CL quantum in experimental studies, we recommend optimizing the CLS depending on the cell type and the ROS‐generating stimulus used. Copyright © 2003 John Wiley & Sons, Ltd.
The acute response of neutrophil function to a bout of judo training
Authors: Chinda Daisuke , Umeda Takashi , Shimoyama Tadashi , Kojima Arata , Tanabe Masaru , Nakaji Shigeyuki , Sugawara Kazuo
Published: October 2003

Intensive exercise training decreases neutrophil functions in athletes. However, no studies to date have investigated the effect of irregular‐interval training, such as is associated with judo training programmes, on neutrophil functions. The purpose of this study was to examine such effects. Thirty‐seven male college judoists participated in this study. Neutrophil oxidative burst activity, phagocytic activity and expression of CD11b and CD16 per cell were measured by ﬂow cytometry before and after judo training. Total neutrophil counts increased signiﬁcantly from 2.98 ± 0.82 to 7.95 ± 1.80 × 103/µL (p < 0.001). The proportion of neutrophils producing reactive oxygen species (ROS) was increased signiﬁcantly (p < 0.001). On the other hand, the phagocytic activity decreased after training, as shown by a decrease in the amount of ingested opsonized zymosan per cell (p < 0.001), possibly as a compensatory effect for the increased numbers of ROS‐producing neutrophils. Expression of CD11b and CD16 per cell decreased by 20% and 30%, respectively, after judo training. In conclusion, judo training induced a decrease in phagocytic activity through the lowered expression of CD11b and CD16 on the surface of neutrophils, and increased the oxidative burst activity of neutrophils. Copyright © 2003 John Wiley & Sons, Ltd.
Cisplatin adducts of d(CCTCTG*G*TCTCC)·d(GGAGACCAGAGG) in aqueous solution by vibrational circular dichroism spectroscopy
Authors: Tsankov D. , Kalisch B. , Van De Sande J. H. , Wieser H.
Published: October 2003

The vibrational circular dichroism (VCD) and IR absorption spectra of a dodecamer d(CCTCTGGTCTCC)·d(GGAGACCAGAGG) coordinated with cisplatin are distinct compared to those of the dodecamer without cisplatin. Although the intensity of PO2/deoxyribose absorptions (1150–850 cm−1) increases noticeably relative to those of the carbonyl and ring deformations of the bases (1750–1500 cm−1), the VCD spectra differ to a much greater extent. Overlapping positive and negative bands can be assigned relatively easily to individual vibrational modes. The effect of platination on the dodecamer duplex is expressed most prominently in VCD arising solely from the vibrations of the guanines bound to the platinum atom. The effect on the VCD features of other bases leads to minute wavenumber shifts at most. These observations are in agreement with previous NMR and X‐ray experiments on the same oligonucleotide. The assignment of the absorption and VCD bands strongly resembles those of the octamer duplex d(CCTGGTCC)·d(GGACCAGG) when coordinated with platinum. The spectra of the dodecamer did not indicate any isomerization of the complex with time, as is clearly the case for the octamer. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 72: 490–499, 2003
Interaction of anticancer drug cisplatin with guanine: Density functional theory and surface‐enhanced Raman spectroscopy study
Authors: Giese Bernd , McNaughton Don
Published: October 2003

Surface‐enhanced Raman spectroscopy (SERS) in a silver sol assisted by density functional theory (DFT) calculations is shown to be a promising tool in the characterization of platinum complexes and their interaction with nucleic acid bases. This is demonstrated using cisplatin and guanine as a model. The energies and geometric parameters of cisplatin, guanine, and their reaction products are calculated at Becke's nonlocal three parameter exchange and correlation functional and the Lee–Yang–Parr correlation functional level using the 6‐31++G(d,p) basis set on the light elements and the effective core potential by Hay and Wadt on platinum. Available X‐ray crystallography data are mostly in agreement with predictions within the experimental precision level, although PtN bond lengths tend to be systematically overestimated. The normal Raman spectrum of cisplatin is assigned. The SERS spectra of cisplatin and its reaction product with guanine are measured from 10−6 M aqueous solution. The observed spectral changes in the SERS spectrum of guanine upon cisplatin binding are modeled by DFT calculations. The best agreement between theory and experiment is achieved when the adsorbed reaction product is assumed to be the 1:1 adduct cis‐Pt(NH3)2ClG in which Pt is bound to N7 and guanine is deprotonated at N9. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Conformation of α zeins in solid state by Fourier transform IR
Authors: Forato Lucimara A. , Bicudo Tatiana De C. , Colnago Luiz A.
Published: October 2003

The major maize storage proteins (α zeins) are deposited as an insoluble mass in the protein bodies of the endosperm. Because they are insoluble in water, most structural studies are performed in alcohol solutions. To solve the question raised by several authors about denaturation of the α zein structure by alcohol, we analyze the secondary structure of α zeins prepared with and without solubilization in alcohol (corn gluten meal and protein bodies with high concentrations of α zeins and traces of β zeins). The secondary structures of α zeins are analyzed in the solid state by Fourier transform IR spectroscopy (FTIR) in KBr pellets and solid‐state 13C‐NMR spectroscopy. The proportion of secondary structures obtained by FTIR of α zeins prepared with and without solubilization in alcohol yield almost identical proportions of α helices and β sheets. The proportion of α helices (43%) agrees with that measured by circular dichroism in an alcohol solution. However, the proportion of β sheets (28%) is higher than the one measured by the same technique. Gluten and protein body samples with high β zein content showed higher β sheet and lower α helix proportions than that obtained for α zein preparations. The solid‐state 13C‐NMR spectra show the carbonyl peak for the α zeins at δ 176 and for the sample rich in β zeins at δ 172, which demonstrates the presence of a high content of α helices and β sheets, respectively. These results indicate that alcohol solubilization does not affect the conformation of α zeins, validating the secondary structure measurements in solution. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Fluorescence resonance energy transfer between donor‐acceptor pair on two oligonucleotides hybridized adjacently to DNA template
Authors: Wang L. , Gaigalas A. K. , Blasic J. , Holden M. J. , Gallagher D. T. , Pires R.
Published: October 2003

We use fluorescein as the energy donor and rhodamine as the acceptor to measure the efficiency of fluorescence resonance energy transfer (FRET) in a set of hybridized DNA constructs. The two fluorophores are covalently attached via linkers to two separate oligonucleotides with fluorescein at the 3′ end of one oligonucleotide and rhodamine at the 5′ end or in the middle of another nucleotide. For the FRET analysis both fluorophore‐labeled oligonucleotides are hybridized to adjacent sections of the same DNA template to form a three‐component duplex with a one base gap between the two labeled oligonucleotides. A similar configuration is implemented for a quantitative real‐time polymerase chain reaction (PCR) with LightCycler technology, where a 1–5 base separation between donor and acceptor is recommended to optimize energy transfer efficiencies. Our constructs cover donor‐acceptor separations from 2 to 17 base pairs (∼10–70 Å). The results show that, when the two fluorophores are located at close distances (less than 8 base separation), FRET efficiencies are above 80%, although there may be ground‐state interactions between fluorophores when the separation is under about 6 bases. Modeling calculations are used to predict the structure of these three‐component constructs. The duplex mostly retains a normal double helical structure, although slight bending may occur near the unpaired base in the DNA template. Stable and reproducible energy transfer is also observed over the distance range investigated here in real‐time thermal cycling. The study identifies important parameters that determine FRET response in applications such as real‐time PCR. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Simple PbII fluorescent probe based on PbII‐catalyzed hydrolysis of phosphodiester
Authors: Sun Ming , Shangguan Dihua , Ma Huimin , Nie Lihua , Li Xiaohua , Xiong Shaoxiang , Liu Guoquan , Thiemann Wolfram
Published: October 2003

A new fluorescent probe for PbII, p‐nitrophenyl 3H‐phenoxazin‐3‐one‐7‐yl phosphoric acid (NPPA), was designed and synthesized by linking resorufin (serving as a fluorophore and electron acceptor) to p‐nitrophenol (serving as a fluorescence quencher and electron donor) through phosphodiester bonds. When NPPA was irradiated with light, intramolecular fluorescence self‐quenching took place because of the photoinduced electron transfer from the donor to the acceptor. However, upon the addition of PbII, the phosphate ester bonds in the probe were cleaved and the fluorophore was released, accompanying the retrievement of fluorescence. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Pinacyanol as effective probe of fibrillar β‐amyloid peptide: Comparative study with Congo Red
Authors: Sabaté Raimon , Estelrich Joan
Published: October 2003

The binding of pinacyanol (PIN), a cationic cyanine dye, to β‐amyloid fibrils (Aβ), which are associated with Alzheimer disease, was quantified by absorption spectrophotometry to measure the concentration of PIN bound to Aβ as a function of the Aβ concentration or by means of the separation of free PIN from bound PIN by centrifugation and subsequent analysis of the supernatant by visible‐absorption spectrophotometry. Both methods gave equivalent results. The stoichiometry of PIN binding to Aβ was 1, and the curve representing the concentration effect of Aβ on the concentration of a dye–Aβ complex showed a biphasic curve instead of the hyperbolic curve that is characteristic of weak ligand–macromolecule interactions [e.g., as shown by Congo Red (CR)]). This and the fact that a Scatchard plot could not be fitted to the experimental data suggested that PIN binds tightly to Aβ. A comparison to the interaction of CR with Aβ led us to conclude that PIN is more sensitive than CR. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Binding of quercetin with human serum albumin: A critical spectroscopic study
Authors: Sengupta Bidisa , Sengupta Pradeep K.
Published: October 2003

Flavonols are plant pigments that are ubiquitous in nature. Quercetin (3,3′,4′,5,7‐pentahydroxyflavone) and other related plant flavonols have come into recent prominence because of their usefulness as anticancer, antitumor, anti‐AIDS, and other important therapeutic activities of significant potency and low systemic toxicity. Quercetin is intrinsically weakly fluorescent in aqueous solution, showing an emission maximum at ∼538 nm. Upon binding to human serum albumin (HSA), quercetin undergoes dramatic enhancement in its fluorescence emission intensity, along with the appearance of dual emission behavior, consisting of normal and excited‐state proton transfer (ESPT) fluorescence. In addition, the occurrence of a third emitting species has been noted for the first time. This is attributed to a electronic ground‐state complex formed in the protein environment. High values of the fluorescence anisotropy (r) are obtained in the presence of HSA for the ESPT tautomer (r = 0.18), as well as the complex species (r = 0.37) of quercetin, indicating that the precursor ground‐state molecules for both these emitting species of quercetin molecules are located in the motionally constrained sites of HSA. The steady‐state emission data suggest that quercetin binds to two distinct sites in HSA from which the emissions from the normal tautomer and complex species take place. The preliminary results of studies on emission decay kinetics are also reported herein. Studies by far‐UV circular dichroism spectroscopy reveal that binding of quercetin induces no significant perturbation in the secondary structure of HSA. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Industry self‐regulation and adverse selection: a comparison across four trade association programs
Authors: Lenox Michael J. , Nash Jennifer
Published: October 2003

In an attempt to avoid costly regulation and liability as a result of externalities, a number of trade associations have promoted industry self‐regulation – the voluntary association of firms to control their collective behavior. However, previous studies have found that, without explicit sanctions for malfeasance, such self‐regulatory programs are likely to attract more polluting firms. In this paper, we examine four environmental self‐regulatory programs in the chemical, textile, and pulp and paper industries. Using a sample of over 4000 firms within these industries, we find evidence that in at least one program more polluting firms tended to join, while in another cleaner firms were more likely to join. We propose that differences in the structure of the programs drive the appearance of this form of adverse selection. In particular, we speculate that only when self‐regulatory programs have explicit sanctions for malfeasance may they avoid adverse selection problems. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment.
Environmental reporting and transport – the case of a public transport company
Authors: Andersen Otto
Published: October 2003

This article discusses corporate environmental reporting in the field of transport. In addition to addressing this issue in general, the article includes empirical material from a case transport company. The process of preparing the year 2000 environmental report for the company is described. The environmental report includes actions for improving the environmental performance of the company, and indicators for monitoring of the progress from year to year. This is based on separate studies of the employees' company travels, daily travel to work and the purchasing of energy. The company is using societal accounting to show its responsibility as an important societal actor, improving the stakeholder dialogue and providing knowledge at the political level. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment.
Physical assessment of patients with anorexia nervosa and bulimia nervosa: an international comparison
Authors: Kovacs D. , Winston A. P.
Published: October 2003

Objective:

A questionnaire study was carried out to determine which investigations were carried out routinely on patients with anorexia nervosa and bulimia nervosa.

Method:

A specially designed questionnaire was sent to 168 clinicians working in the field of eating disorders in 25 countries. Respondents were asked to supply information about how often they carry out specific investigations on new patients with AN and BN. The questionnaire covered the use of physical examination, biochemical and haematological tests and cardiac investigations.

Results:

71 (42.3 per cent) questionnaires were returned. Biochemical investigations and full blood counts were carried out frequently. Significant differences were found between AN patients and BN patients in the measurement of calcium, phosphate and magnesium levels. In some cases, patients with BN were not routinely assessed for hypokalaemia. Micronutrient levels were measured rarely and only 40 per cent of respondents carried out routine electrocardiograms (ECGs) in AN.

Discussion:

Measurement of serum potassium should be routine in BN and other electrolytes should probably measured more often in both disorders. Detection of treatable micronutrient deficiencies should be given more emphasis and the ECG should become a routine investigation in AN. Copyright © 2003 John Wiley & Sons, Ltd and Eating Disorders Association.
Validation of a screening instrument for identifying risk behaviour related to eating disorders
Authors: Waaddegaard Mette , Thoning Henrik , Petersson Birgit
Published: October 2003

Objective:

To validate a screening instrument (RiBED‐8) aimed at identifying risk behaviour related to eating disorders among Danish adolescents in a two‐stage study in 1996 and a follow‐up study 2.75 years later.

Methods:

2094 pupils, aged 14–21 years, responded to a 49‐item self‐report questionnaire. Risk behaviour related to eating disorders was defined. The psychometric validation procedure was performed with Rasch Item analysis, testing the internal and external homogeneity, local independence and uni‐dimensionality. Furthermore, 91 semi‐structured clinical interviews were conducted to create a gold standard and to test the content, criterion and construct related validity of risk behaviour. Eight items comprised the final scale, called RiBED‐8. Furthermore, the criterion‐related validity, the stability and the predictive validity of RiBED‐8 was tested using the Eating Disorders Inventory (EDI‐2) in the follow‐up study in 1998, where 508 pupils responded. In a cross‐sectional design in 1998, the concurrent general psychopathology was analysed using Hopkins Symptoms CheckList (SCL‐90‐R). Lastly, the time‐related reliability of the instrument was tested by test–retest analysis in 1998.

Results:

The scale was a uni‐dimensional screening instrument with local independence, internal consistency and external homogeneity towards age groups. However, the instrument did not measure less severe risk behaviour for boys. RiBED‐8 had sufficiently good psychometric properties (construct, criterion and predictive validity and test–retest reliability), and identified persons with a high level of general psychological distress and of eating pathology. Risk behaviour related to eating disorders was stable and indicated a 5.6‐times greater relative risk of having eating disorders over 2.75 years. Copyright © 2003 John Wiley & Sons, Ltd and Eating Disorders Association.
Wind erosion in a marginal Mediterranean dryland area: a case study from the Khanasser Valley, Syria
Authors: Masri Z. , Zöbisch M. , Bruggeman A. , Hayek P. , Kardous M.
Published: October 2003

Evidence of wind erosion is widespread in the drylands of the Mediterranean region. The purpose of this study was to quantify the extent of windblown dust and to assess the factors that affect the susceptibility to wind erosion in areas that are marginal due to their aridity. The study was carried out in Khanasser Valley, a typical degraded, marginal area in northwestern Syria. The average annual rainfall is about 200 mm and falls mainly in the winter months. In the valley ﬂoor, cultivation of rainfed barley using conventional tillage has spread over the past decades due to mechanization, reducing the area of natural grazing land. After harvest, the stubble is grazed by sheep leaving the land bare and vulnerable to wind erosion during the following hot and dry summer months. BSNE (Big Spring Number Eight) samplers were installed to sample the horizontal ﬂux of airborne dust during the summer months of 1998–2001 at two land uses in the study area, i.e. on natural grazing land and on harvested and grazed barley ﬁelds. Sediment samples were collected at weekly intervals. The average daily mass ﬂux of airborne material for the 5 to 100 cm height was 0·285 g cm−1 width for the cropland, as compared to 0·089 g cm−1 width for the degraded grazing land. During two of the four seasons, more than 45 per cent of the total airborne sediment trapped for the season was captured during a single week, at both landuse locations. The quantity of airborne materials transported by wind was related to the wind factor, soil management and surface conditions. Nutrient and organic matter content of the airborne sediments exceeded the amounts in the parent soils, indicating that wind erosion could contribute to nutrient depletion of the source areas. Copyright © 2003 John Wiley & Sons, Ltd.
Simulations to optimize sampling of aeolian sediment transport in space and time for mapping
Authors: Chappell Adrian , McTainsh Grant , Leys John , Strong Craig
Published: October 2003

The sampling frequency in space and time is often inadequate to estimate the accuracy and precision of aeolian sediment transport. The problem stems from a lack of knowledge about the spatial and temporal scale of variation in aeolian transport and is compounded by a shortage of resources (aeolian sediment traps and labour). This study developed a geostatistical methodology for estimating sediment transport at unsampled locations and tested the extent to which it was dependent on sampling networks (nested, grid and random) and frameworks (mobile or static sampling framework between wind erosion events). Aeolian transport data were collected in an area of Australia inﬂuenced by wind erosion (Diamantina Lakes National Park, southwestern Queensland) to evaluate the combination of events used for mapping transport. Insufﬁcient wind erosion events occurred to test sediment sampling strategies and hence simulated sampling was conducted using maps of sediment transport produced with existing models of aeolian sediment transport in the same study area. Independent validation data were used to test the estimation performance.

The results suggested that sampling networks that did not include information on the spatial scale of variation (i.e. grid and random sampling) did not represent adequately the sediment transport population. In contrast, a bespoke nested sampling network performed consistently better than the other networks. Overall the static framework with a nested network was recommended for estimation and mapping of sediment transport with few resources and was likely to be especially important for use over large areas. This approach has the advantage of requiring only a single pooled within‐event variogram for sediment transport to be used to derive the model parameters for kriging or stochastic simulation for each event. Copyright © 2003 John Wiley & Sons, Ltd.
Measurement and simulation of wind erosion, roughness degradation and residue decomposition on an agricultural field
Authors: van Donk Simon J. , Skidmore Edward L.
Published: October 2003

The Wind Erosion Prediction System (WEPS) includes submodels to simulate soil erosion by wind, roughness degradation and residue decomposition. These WEPS submodels were tested using data measured on a 600 m by 415 m farmer's ﬁeld, planted with winter wheat, near Burlington, Colorado, USA. Big Spring Number Eight (BSNE) samplers were used to measure wind blown sediment ﬂux and automated devices (Sensits) detected saltating sediment. A weather station recorded relevant meteorological data. Detailed measurements of ﬁeld surface conditions were taken on three dates. One signiﬁcant dust storm occurred during the experimental period (November 2000 to April 2001). Spatial variability of sediment discharge was high. This could partially be explained by spatial differences in residue cover and mass, leaf area index, sand fraction and wetness of the surface soil.

WEPS overestimated the ability of small wheat plants to protect the soil against wind erosion. A simulation without any wheat plants produced a large ﬁeld sediment loss of 4·43 kg m−2, whereas a simulation with very small wheat plants (height = 10 mm, leaf area index = 0·1, stem area index = 0·01) produced no erosion. This component of WEPS is based on laboratory wind tunnel experiments with simulated standing biomass uniformly spaced on a ﬂat surface. Wheat biomass in the ﬁeld is not uniformly spaced. WEPS should be modiﬁed to account for these non‐uniform realities.

Mean ridge height was reduced from 42 mm on 19 December to 34 mm (36 mm simulated using WEPS) on 12 April. Mean random roughness was reduced from 5·8 mm on 19 December to 5·2 mm (5·3 mm simulated) on 8 March. Mean corn residue biomass was reduced only slightly from 1204 kg ha−1 on 19 December to 1174 kg ha−1 (1075–1175 kg ha−1 simulated) on 12 April. These differences between measured data and simulations were not signiﬁcant (P > 0·05), enhancing conﬁdence in the ability of WEPS to simulate roughness degradation and residue decomposition. Published in 2003 by John Wiley & Sons, Ltd.
Integrative nuclear FGFR1 signaling (INFS) as a part of a universal “feed‐forward‐and‐gate” signaling module that controls cell growth and differentiation
Authors: Stachowiak Michal K. , Fang Xiaohong , Myers Jason M. , Dunham Star M. , Berezney Ronald , Maher Pamela A. , Stachowiak Ewa K.
Published: October 2003

A novel signaling mechanism is described through which extracellular signals and intracellular signaling pathways regulate proliferation, growth, differentiation, and other functions of cells in the nervous system. Upon cell stimulation, fibroblast growth factor receptor‐1 (FGFR1), a typically plasma membrane‐associated protein, is released from ER membranes into the cytosol and translocates to the cell nucleus by an importin‐β‐mediated transport pathway along with its ligand, FGF‐2. The nuclear accumulation of FGFR1 is activated by changes in cell contacts and by stimulation of cells with growth factors, neurotransmitters and hormones as well as by a variety of different second messengers and thus was named integrative nuclear FGFR1 signaling (INFS). In the nucleus, FGFR1 localizes specifically within nuclear matrix‐attached speckle‐domains, which are known to be sites for RNA Pol II‐mediated transcription and co‐transcriptional pre‐mRNA processing. In these domains, nuclear FGFR1 colocalizes with RNA transcription sites, splicing factors, modified histones, phosphorylated RNA Pol II, and signaling kinases. Within the nucleus, FGFR1 serves as a general transcriptional regulator, as indicated by its association with the majority of active nuclear centers of RNA synthesis and processing, by the ability of nuclear FGFR1 to activate structurally distinct genes located on different chromosomes and by its stimulation of multi‐gene programs for cell growth and differentiation. We propose that FGFR1 is part of a universal “feed‐forward‐and‐gate” signaling module in which classical signaling cascades initiated by specific membrane receptors transmit signals to sequence specific transcription factors (ssTFs), while INFS elicited by the same stimuli feeds the signal forward to the common coactivator, CREB‐binding protein (CBP). Activation of CBP by INFS, along with the activation of ssTFs by classical signaling cascades brings about coordinated responses from structurally different genes located at different genomic loci. © 2003 Wiley‐Liss, Inc.
Medulloblastoma cell invasion is inhibited by green tea (−)epigallocatechin‐3‐gallate
Authors: Pilorget Anthony , Berthet Virginie , Luis José , Moghrabi Albert , Annabi Borhane , Béliveau Richard
Published: October 2003

Epigallocatechin‐3‐gallate (EGCG), the major green tea polyphenol, can reach the brain following oral intake and could thus act as an anti‐tumoral agent targeting several key steps of brain cancer cells invasive activity. Because integrin‐mediated extracellular matrix recognition is crucial during the cell adhesion processes involved in carcinogenesis, we have investigated the effects of EGCG on different cellular integrins of the pediatric brain tumor‐derived medulloblastoma cell line DAOY. Using flow cytometry, we report the levels of expression of several cell surface integrins in DAOY. These include high expression of α2, α3, and β1 integrins, as well as αv and β3 integrins. Moreover, we provide evidence that EGCG can antagonize DAOY cell migration specifically on collagen by increasing cell adhesive ability through specific gene and protein upregulation of the β1 integrin subunit. Our results suggest that this naturally occurring green tea polyphenol may thus be used as a nutraceutical therapeutic agent in targeting the invasive character of medulloblastomas. © 2003 Wiley‐Liss, Inc.
Phosphorylation of PPARγ via active ERK1/2 leads to its physical association with p65 and inhibition of NF‐κβ
Authors: Chen Fei , Wang Muchun , O'Connor J. Patrick , He Mai , Tripathi Tushar , Harrison Lawrence E.
Published: October 2003

Peroxisome proliferator‐activated receptors (PPAR) are novel nuclear receptors and PPARγ ligands have been shown to produce pro‐apoptotic effects in many cancer cell types, including colon cancer. PPARγ ligands exert their effect through PPARγ‐dependent (genomic) and PPARγ‐independent (non‐genomic) mechanisms. Recent evidence suggests that PPARγ ligands exert their pro‐apoptotic effects in part by directly antagonizing the NF‐κβ pathway as well as through activation of the MAP kinase pathway. In this report, we have demonstrated that ciglitazone, a member of the thiazoldinedione class of PPARγ ligands induces HT‐29 colon cancer cells to undergo apoptosis and prior to apoptosis, ciglitazone exposure results in a transient phosphorylation of PPARγ. This phosphorylation of PPARγ was mediated through the ciglitazone‐induced activation of Erk1/2. PPARγ phosphorylation affected the genomic pathway by being inhibitory to PPARγ–DNA binding and PPRE transcriptional activity, as well as the non‐genomic pathway by increasing the physical interaction of PPARγ with p65, leading to the inhibition of NF‐κβ. Ciglitazone induced phosphorylation of PPARγ through the MAP kinase pathway provides a potential regulatory mechanism for PPARγ's physical interaction with p65, leading to inhibition of NF‐κβ and subsequent apoptosis. © 2003 Wiley‐Liss, Inc.
Matrix GLA protein and BMP‐2 regulate osteoinduction in calcifying vascular cells
Authors: Zebboudj Amina F. , Shin Victoria , Boström Kristina
Published: October 2003

Expression of matrix GLA protein (MGP), an alleged calcification inhibitor, is increased in calcified arteries. We used calcifying vascular cells (CVC) that form calcified nodules in vitro to clarify the importance of MGP in vascular cell calcification and differentiation. Unexpectedly, MGP dose‐dependently increased calcification in CVC. It also increased expression of the osteogenic marker Cbfal, while decreasing expression of the smooth muscle marker α‐actin as assessed by immunoblotting. Bone morphogenetic protein‐2 (BMP‐2), a known osteoinductive factor also increased calcification and osteogenic differentiation in CVC. We hypothesized that the effect of MGP was linked to that of BMP‐2 since previous studies show that MGP modulates BMP‐2 activity. Therefore, we compared the effect of MGP at different levels of exogenous BMP‐2. Results showed that high BMP‐2 levels significantly increased the stimulatory effect of low levels of MGP. A relative inhibition of calcification was observed at intermediate levels of MGP and a trend towards renewed stimulation at high levels of MGP. Thus, addition of MGP either promoted or inhibited calcification, depending on the relative amounts of BMP‐2 and MGP. This was confirmed in human CVC with different relative expression of BMP‐2 and MGP. Calcification in CVC with high relative expression of BMP‐2 was inhibited by MGP, while calcification in CVC with low relative expression of BMP‐2 was stimulated by MGP. MGP and BMP‐2 both accelerated nodule formation, but had opposite effects on nodule size; MGP decreased while BMP‐2 increased nodule size. The effect of BMP‐2 may partly be explained by a BMP‐2 induced decrease in MGP expression. Together, our results suggest that the effect of MGP on calcification and osteogenic differentiation is determined by availability of BMP‐2. © 2003 Wiley‐Liss, Inc.
Nuclear matrix bound fibroblast growth factor receptor is associated with splicing factor rich and transcriptionally active nuclear speckles
Authors: Somanathan Suryanarayan , Stachowiak Ewa K. , Siegel Alan J. , Stachowiak Michal K. , Berezney Ronald
Published: October 2003

We have used confocal microscopy combined with computer image analysis to evaluate the functional significance of a constitutively expressed form of the receptor tyrosine kinase FGFR1 (fibroblast growth factor receptor 1) in the nucleus of rapidly proliferating serum stimulated TE 671 cells, a medullobastoma human cell line. Our results demonstrate a limited number of large sites and numerous smaller sites of FGFR1 in the nuclear interior. The larger sites showed virtually complete colocalization (>90%) with splicing factor rich nuclear speckles while the smaller sites showed very limited overlap (<20%). Similar results were found for several other proliferating cell lines grown in culture. An in situ transcription assay was used to determine colocalization with transcription sites by incorporating 5‐bromouridine triphosphate (BrUTP) followed by dual staining for BrUTP and FGFR1. These results combined with those from using an antibody against the large subunit of RNA polymerase II suggest a significant degree of colocalization (26–38%) over both the large and small sites. No colocalization was detected with sites of DNA replication. The spatial arrangements of FGFR1 sites and colocalization with nuclear speckles were maintained following extraction for nuclear matrix. Moreover, immunoblots indicated a significant enrichment of FGFR1 in the nuclear matrix fraction. Our findings suggest an involvement of a nuclear matrix bound FGFR1 in transcriptional and RNA processing events in the cell nucleus. We further propose that nuclear speckles, aside from a role in transcriptional/RNA processing events, may serve as fundamental regulatory factories for the integration of diverse signaling and regulatory factors that impact transcription and cellular regulation. © 2003 Wiley‐Liss, Inc.
Annulus cells release ATP in response to vibratory loading in vitro
Authors: Yamazaki Satoru , Weinhold Paul S. , Graff Ronald D. , Tsuzaki Mari , Kawakami Mamoru , Minchew Joe T. , Banes Albert J.
Published: October 2003

Mechanical forces regulate the developmental path and phenotype of a variety of tissues and cultured cells. Vibratory loading as a mechanical stimulus occurs in connective tissues due to energy returned from ground reaction forces, as well as a mechanical input from use of motorized tools and vehicles. Structures in the spine may be particularly at risk when exposed to destructive vibratory stimuli. Cells from many tissues respond to mechanical stimuli, such as fluid flow, by increasing intracellular calcium concentration ([Ca2+]ic) and releasing adenosine 5′‐triphosphate (ATP), extracellularly, as a mediator to activate signaling pathways. Therefore, we examined whether ATP is released from rabbit (rAN) and human (hAN) intervertebral disc annulus cells in response to vibratory loading. ATP release from annulus cells by vibratory stimulation as well as in control cells was quantitated using a firefly luciferin‐luciferase assay. Cultured hAN and rAN cells had a basal level of extracellular ATP ([ATP]ec) in the range of 1–1.5 nM. Vibratory loading of hAN cells stimulated ATP release, reaching a net maximum [ATP] within 10 min of continuous vibration, and shortly thereafter, [ATP] declined and returned to below baseline level. [ATP] in the supernatant fluid of hAN cells was significantly reduced compared to the control level when the cells received vibration for longer than 15 min. In rAN cells, [ATP] was increased in response to vibratory loading, attaining a level significantly greater than that of the control after 30 min of continuous vibration. Results of the current study show that resting annulus cells secrete ATP and maintain a basal [ATP]ec. Annulus cells may use this nucleotide as a signaling messenger in an autocrine/paracrine fashion in response to vibratory loading. Rapid degradation of ATP to ADP may alternatively modulate cellular responses. It is hypothesized that exposure to repetitive, complex vibration regimens may activate signaling pathways that regulate matrix destruction in the disc. As in tendon cells, ATP may block subsequent responses to load and modulate the vibration response. Rabbit annulus cells were used as a readily obtainable source of cells in development of an animal model for testing effects of vibration on the disc. Human cells obtained from discarded surgical specimens were used to correlate responses of animal to human cells. © 2003 Wiley‐Liss, Inc.
Scaffold attachment factors SAFB1 and SAFB2: Innocent bystanders or critical players in breast tumorigenesis?
Authors: Oesterreich Steffi
Published: October 2003

Scaffold attachment factor B1 (SAFB1) and SAFB2 are large, multifunctional proteins that have been implicated in numerous cellular processes including chromatin organization, transcriptional regulation, RNA splicing, and stress response. While the two homologous proteins show high similarity, and functional domains are highly conserved, evidence suggests that they also have unique properties. For example, SAFB2 can be found in both the nucleus and cytoplasm, whereas SAFB1 seems to be mainly localized in the nucleus. In breast cancer cells, SAFBs function as estrogen receptor corepressors and growth inhibitors. SAFB protein expression is lost in approximately 20% of breast cancers. Interestingly, the two genes reside in close proximity, oriented head‐to‐head, on chromosome 19p13, a locus which is frequently lost in clinical breast cancer specimens. Furthermore, SAFB1 mutations have been identified in breast tumors that were not present in adjacent normal tissue. The possibility that SAFB1 and SAFB2 are novel breast tumor suppressor genes, and how they might function in this role, are discussed. © 2003 Wiley‐Liss, Inc.
Alternative splicing of fibronectin mRNAs in chondrosarcoma cells: Role of far upstream intron sequences
Authors: Flanagan Matthew , Liang Hongyan , Norton Pamela A.
Published: October 2003

The fibronectin (FN) gene encodes multiple mRNAs through the process of alternative splicing, and production of certain isoforms is characteristic of a given cell type. Chondrocytes produce FNs that completely lack alternative exon EIIIA, and loss of inclusion of the exon is tightly linked to chondrogenic condensation of mesenchymal cells. The inclusion of a second exon, EIIIB, is high in embryonic cartilage, but declines with age. Multiple exons are omitted to produce the (V + C)‐form that is highly specific for cartilage and chondrocytes. A rat chondrosarcoma cell line, RCS, was identified that preserves key features of the cartilage‐specific splicing phenotype. RCS cells, which exclude exon EIIIA, and HeLa cells, which include exon EIIIA similar to mesenchymal cells, were used to assess the contribution of intron sequences flanking exon EIIIA to splicing regulation. Deletion of most of the intron downstream of the exon had little effect on splicing in either cell type. However, deletions within upstream intron 32‐A reduced inclusion of the alternative exon in both cell types. The sequences involved lie more than 200 nucleotides away from the exon, but could not be localized to a single region by deletion mapping. These intronic sequences contribute to the efficiency of exon EIIIA recognition, but not to cell‐type specific regulation. The normally inhibitory factor polypyrimidine tract binding protein promotes exon EIIIA inclusion in a manner that is partially dependent on the regulatory sequences within intron 32‐A. © 2003 Wiley‐Liss, Inc.