bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of midlatitude and tropical overturning circulation on the isotopic composition of atmospheric water vapor and Antarctic precipitation
Authors: Noone David
Published: February 2008

While isotope records from ice cores are known to reflect temperature, this must be associated with zonally symmetric circulation. A new conceptual depiction of the isotopic cycling is established by considering the overturning circulation in isentropic coordinates. In this depiction, poleward transport of air and water vapor is non‐diffusive, in a way that is similar to that depicted by Rayleigh models. However, the equatorward return flow is also important since it is this which is supplied with water by surface evaporation. The isotopic state emerges as a balance between evaporative supply and poleward advection, and removes the need to assume some initial source condition for an open distillation. Model experiments that simulate a wide range of circulation strengths show the isotopic composition of Antarctic snow is strongly linked to the strength of midlatitude (eddy driven) circulation, which in turn is driven by meridional temperature differences. Antarctic isotopes are largely independent of the tropical (Hadley) circulation because the rate of advective transport from the tropics to the polar region exceeds the rate at which surface sources replenish the poleward moving air stream. Across all simulations and between seasons, the relationship between δ18O in Antarctica above 1500 m and local surface air temperature is found to be remarkably robust at around 0.69‰/K in winter, 0.85‰/K in summer and with a seasonal slope of 0.60‰/K. Because these slopes result from changes in circulation, isotope records from the continent interior can be considered indicative of the history of overturning circulation.
Use of MISR measurements to study the radiative transfer of an isolated convective cloud: Implications for cloud optical thickness retrieval
Authors: Cornet C. , Davies R.
Published: February 2008

Radiative transfer simulations of an isolated deep convective cloud reconstructed with stereo‐techniques from the Multiangle Imaging Spectroradiometer (MISR) are compared with the reflectances measured at the nine MISR viewing angles. The simulations were done using a three dimensional Monte Carlo model, in which ocean reflectance, aerosol and Rayleigh scattering were prescribed to match the surrounding clear‐sky MISR measurements. Making reasonable assumptions regarding the vertical and horizontal distribution of the volume extinction coefficient, we were able to reproduce the MISR measurements with the 3D radiative calculations. While the uniqueness of the these distributions cannot be proven, they all lead to retrievals of much larger cloud optical thickness and cloud water content than for a 1D retrieval. Averaged over the cloud, the difference was a factor of about 3, rising to 9 locally. This is a consequence of horizontal photon transport that serves to highlight the inadequacy of 1D retrievals for the case of deep convective cloud. Concerning the internal cloud properties, we noticed the angular distribution of modeled radiances did not match the measured radiances when an ice crystal phase function was applied. Better estimates of the optical depths and water contents of deep convective clouds appear to be obtainable by integrating an estimate of the extinction coefficient over the vertical cloud extent (when this can assessed) than by attempting to invert the radiance measured from a single‐angle view using 1D theory.
Validation of MODIS derived aerosol optical depth over Western India
Authors: Misra Amit , Jayaraman A. , Ganguly Dilip
Published: February 2008

MODIS (Moderate Resolution Imaging Spectroradiometer) derived aerosol optical depths (AODs) were compared against the ground based observations from Microtops sunphotometer over Ahmedabad (72.5°E, 23.03°N) in Western India. The region is semi‐arid and poses challenge for the satellite remote sensing of aerosols. Besides comparing the ground truth with the Collection Version 4 of MODIS aerosol product, the paper reports the first ever validation of the updated Collection Version 5 of the MODIS aerosol product over India. The AOD data from Aqua platform is averaged over 0.5° × 0.5° centered at Ahmedabad and compared with the sunphotometer observation taken within half an hour to the satellite overpass time. The Version 4 data comparison showed a large scatter. Further, the comparison for 470 nm and 660 nm behave differently over different years. Overall, the comparison shows considerable improvement in the Collection Version 5 aerosol product. Among seasons, Pre‐Monsoon (April to May) has the best correlation and Dry season (December to March) the least. The updated product has scope for further improvement as the correlations are less than unity, and the extent of underestimation for 470 nm is more during Dry and Post‐Monsoon seasons whereas that for 660 nm is more during Pre‐Monsoon and Monsoon seasons which are dominated by fine and coarse particles respectively. The results show a better surface reflectance parameterization by the MODIS Collection Version 5 algorithm as compared to Version 4 but the aerosol model used in the retrieval algorithm is still not adequate.
Carbonate preservation in marine sediments: Mid to higher latitude quantitative proxies
Authors: Loubere Paul , Chellappa Rebecca
Published: February 2008

Observations of carbonate preservation in marine sediments have long been used to infer changes in ocean circulation or biogenic production. When combined with measures of organic carbon rain and calcite accumulation rates, quantitative estimates of changes in preservation can reveal variation in biogenic fluxes, the org. C to calcite flux ratio and saturation state of bottom waters. Here we develop quantitative dissolution proxies for mid to higher latitudes based on foraminiferal test fragmentation. Examining surface sediments, we find that fragmentation in G. bulloides and G. truncatulinoides is linear with increasing seabed dissolution rate and can be used to quantify changes in carbonate preservation. G. truncatulinoides shows a constant relationship of fragmentation to dissolution. However, we observe that, although linear to dissolution rate, the fragmentation in G. bulloides depends on which morphotype is present. Other species, such as G. inflata, have complex responses to increasing dissolution and are less direct preservation indicators.
Ionospheric drift measurements: Skymap points selection
Authors: Kouba D. , Boška J. , Galkin I. A. , Santolík O. , Šauli P.
Published: February 2008

In this paper we concentrate on the plasma drift measurement performed by Digisonde Portable Sounder DPS 4 developed by the UMLCAR, Lowell. Special attention is paid to the quality control of data acquired prior to drift velocity calculations. Risks of carefree use of raw Doppler spectra for the plasma motion analysis have been recognized in the Digisonde community. In this paper we propose improvements of Digisonde drift data processing for velocity evaluation and provide a detailed step‐by step description: (1) robust height range selection, (2) setting limits on the Doppler frequency shift, and (3) setting limits on the echo arrival angle. Raw data that passed our quality control were then used to derive three velocity components of the bulk plasma drift in the ionosphere. In the paper we discuss, in detail, application of the method on the DPS measurements. However, this technique can be efficiently applied on any other digital ionosondes drift data processing.
Calibration of hydrological model GR2M using Bayesian uncertainty analysis
Authors: Huard David , Mailhot Alain
Published: February 2008

An outstanding issue of hydrological modeling is the adequate treatment of uncertainties in model calibration and prediction. The current paradigm is that the major sources of uncertainties, namely input, output and model uncertainty should be accounted for directly, instead of assuming they can be safely lumped into the output uncertainties. In this paper, Bayesian analysis is used to calibrate the conceptual hydrologic monthly model GR2M taking into account input, output, structural and initial state uncertainty through error models and priors. Calibration is performed under different error assumptions to study the influence of the initial state uncertainty, the consequences of large input errors, the impact of error assumptions on calibrated parameter posterior distributions and the definition of error models. It is shown how such an analysis can be used to separate, a posteriori, the different sources of errors, and in particular, to identify structural errors from data errors.
Behavior of the mass transfer coefficient during the MADE‐2 experiment: New insights
Authors: Guan Jianyong , Molz Fred J. , Zhou Quanlin , Liu Hui Hai , Zheng Chunmiao
Published: February 2008

Using a dual‐porosity transport model, a more complete analysis of the MADE‐2 experiment, a natural gradient tracer (tritium) test, is presented. Results show that a first‐order, mass transfer rate coefficient is scale‐dependent and decreasing with experiment duration. This is in agreement with previous studies and predictions. Factors contributing to the scale‐dependency are errors or approximations in boundary conditions, hydraulic conductivity (K) measurements and interpolations, mass transfer rate expressions and conceptual errors in model development. In order to formulate a self‐consistent, dual‐porosity model, it was necessary to assume that the injected tracer was trapped hydraulically in the vicinity of the injection site. This was accomplished by lowering all K values near the injection site by a factor of 30, while holding all other K values, boundary conditions and parameters at their measured or estimated magnitudes. Resulting simulations, using the same scale‐dependent mass transfer rate coefficient, were then able to reasonably match the movement of the center of mass, overall plume geometry and the anomalous mass recovery ratios observed at each snapshot. The dual‐porosity model is conceptually simple, relatively easy to apply mathematically and it simulates differences in advection that are probably the root cause of dispersion in natural heterogeneous sediments. Also, a small more realistic amount of local hydrodynamic dispersion is not precluded.
Shortcomings of linear programming in optimizing river basin allocation
Authors: Ilich Nesa
Published: February 2008

Numerous computer models for river basin planning and management have been developed and used extensively since the mid‐1970s. Early developments have relied on the use of network flow algorithms (NFA), due mainly to higher execution speed than the standard Simplex solvers. However, subsequent efforts to include proper modeling of hydraulic and hydrologic constraints introduced iterative schemes into the NFA‐based models, which diminished the initial advantages in execution speed and which also caused concerns over the accuracy of the convergence schemes. Hence full‐blown commercial linear programming (LP) solvers were introduced as a replacement to the iterative solution strategy of the NFA approach. This paper demonstrates one possible failure to solve a simple allocation problem using the NFA‐based model and shows how this problem can be solved using the standard LP approach. It then identifies cases when even a full‐blown LP approach cannot properly model two critical aspects of river basin management, one related to reservoirs with multiple outflows and the other one related to modeling of hydrologic channel routing. For NFA‐based models the failures are the result of the inability to include relationships between flows on different model components directly into the search process. For the models based on LP solvers, the failures are caused by the fact that integrated reservoir outflow capacity between the starting and the ending storage levels is assumed over the entire length of the assumed time step, while the actual outflow can only take place during the portion of the time step when the storage level is above the invert of the outlet structure.
N‐Acetylcysteine prevents ifosfamide‐induced nephrotoxicity in rats
Authors: Chen N , Aleksa K , Woodland C , Rieder M , Koren G
Published: February 2008

Background and purpose:

Ifosfamide nephrotoxicity is a serious adverse effect for children undergoing cancer chemotherapy. Our recent in vitro studies have shown that the antioxidant N‐acetylcysteine (NAC), which is used extensively as an antidote for paracetamol (acetaminophen) poisoning in children, protects renal tubular cells from ifosfamide‐induced toxicity at a clinically relevant concentration. To further validate this observation, an animal model of ifosfamide‐induced nephrotoxicity was used to determine the protective effect of NAC.

Experimental approach:

Male Wistar albino rats were injected intraperitoneally with saline, ifosfamide (50 or 80 mg kg−1 daily for 5 days), NAC (1.2 g kg−1 daily for 6 days) or ifosfamide+NAC (for 6 days). Twenty‐four hours after the last injection, rats were killed and serum and urine were collected for biochemical analysis. Kidney tissues were obtained for analysis of glutathione, glutathione S‐transferase and lipid peroxide levels as well as histology analysis.

Key results:

NAC markedly reduces the severity of renal dysfunction induced by ifosfamide with a significant decrease in elevations of serum creatinine (57.8±2.3 vs 45.25±2.1 μmol l−1) as well as a reduced elevation of β2‐microglobulin excretion (25.44±3.3 vs 8.83±1.3 nmol l−1) and magnesium excretion (19.5±1.5 vs 11.16±1.5 mmol l−1). Moreover, NAC significantly improved the ifosfamide‐induced glutathione depletion and the decrease of glutathione S‐transferase activity, lowered the elevation of lipid peroxides and prevented typical morphological damages in renal tubules and glomeruli.

Conclusions and implications:

Our results suggest a potential therapeutic role for NAC in paediatric patients in preventing ifosfamide nephrotoxicity.

British Journal of Pharmacology (2008) 153, 1364–1372; doi:10.1038/bjp.2008.15; published online 18 February 2008
Agonists at PPAR‐γ suppress angiotensin II‐induced production of plasminogen activator inhibitor‐1 and extracellular matrix in rat cardiac fibroblasts
Authors: Hao G‐H , Niu X‐L , Gao D‐F , Wei J , Wang N‐P
Published: February 2008

Background and purpose:

Peroxisome proliferator‐activated receptor (PPAR)‐γ ligands have been shown to inhibit cardiac fibrosis. However, the underlying mechanisms are poorly understood. We investigated the regulation by PPAR‐γ ligands of angiotensin (Ang) II‐induced plasminogen activator inhibitor (PAI)‐1, extracellular matrix (ECM) production and cell growth in cardiac fibroblasts.

Experimental approach:

The effects of PPAR‐γ ligands on Ang II‐induced PAI‐1, ECM expression and cell growth were assessed in primary‐cultured rat cardiac fibroblasts; cardiac PAI‐1 and ECM production was examined in Ang II‐infused rats.

Key results:

In growth‐arrested cardiac fibroblasts, PPAR‐γ ligands rosiglitazone and 15‐deoxy‐Δ12,14‐prostaglandin J2 (15d‐PGJ2) dose‐dependently attenuated Ang II‐induced cell proliferation and expression of PAI‐1, collagen type‐I, collagen type‐III and fibronectin. An accompanying increase in PPAR‐γ expression and activation was also observed. These suppressive effects were attenuated by the PPAR‐γ antagonists GW9662 and bisphenol A diglycidyl ether (BADGE). Moreover, rosiglitazone and 15d‐PGJ2 inhibited in part the expression and phosphorylation of Ang II‐induced transforming growth factor (TGF)‐β1, Smad2/3 and c‐Jun NH(2)‐terminal kinase (JNK). Ang II infusion in rats markedly increased left ventricular production of PAI‐1, collagen and fibronectin, with a concurrent increase in the ratios of heart weight/body weight and left ventricle weight/body weight. Co‐treatment with rosiglitazone significantly decreased these levels and upregulated PPAR‐γ expression.

Conclusions and implications:

Rosiglitazone and 15d‐PGJ2 suppress Ang II‐induced production of PAI‐1 and ECM probably via interactions between PPAR‐γ and TGF‐β1/Smad2/3 and JNK signalling pathways. It is suggested that PPAR‐γ and its ligands may have potential applications in preventing cardiac fibrosis.

British Journal of Pharmacology (2008) 153, 1409–1419; doi:10.1038/bjp.2008.21; published online 18 February 2008
Activation of ETBreceptors regulates the abundance of ET‐1 mRNA in vascular endothelial cells
Authors: Farhat N , Matouk C C , Mamarbachi A M , Marsden P A , Allen B G , Thorin E
Published: February 2008

Background and purpose:

The factors that influence the cellular levels of endothelin‐1 (ET‐1) include transcription, mRNA localization, stability and translation, post‐translational maturation of preproET‐1 and degradation of ET‐1. We investigated the regulation of ET‐1 mRNA abundance by extracellular ET‐1 in porcine aortic endothelial cells (PAECs).

Experimental approach:

Passsage one cultures of PAECs were incubated in starving medium in the presence or absence of ET‐1 and antagonists or pharmacological inhibitors. PreproET‐1 mRNA,endothelin‐1promoter activity, Erk and p38 MAPK activation were determined.

Key results:

Exogenous ET‐1 reduced cellular ET‐1 mRNA content: a reduction of 10 000‐fold was observed after 4 h. ET‐1 simultaneously reduced the stability of ET‐1 mRNA and increased the loading of RNA Polymerase II at theendothelin‐1promoter. In the absence of exogenous ET‐1, the ETB‐selective antagonist, BQ788, increased ET‐1 mRNA. An ETA‐selective antagonist had no effect. ET‐1 mRNA returned to control levels within 24 h. Whereas activation of p38 MAPK induced by ET‐1 peaked at 30 min and returned to control levels within 90 min, Erk1/2 remained active after 4 h of stimulation. Inhibition of p38 MAPK prevented the ET‐1‐induced decrease in ET‐1 mRNA. In contrast, Erk1/2 inhibition increased ET‐1 mRNA. Similarly, inhibition of receptor internalization increased ET‐1 mRNA in the presence or absence of exogenous ET‐1.

Conclusions and implications:

These results suggest that extracellular ET‐1 regulates the abundance of ET‐1 mRNA in PAECs, in an ETBreceptor‐dependent manner, by modulating both mRNA stability and transcription via mechanisms involving receptor endocytosis and both ERK and p38 MAPK pathways.

British Journal of Pharmacology(2008)153, 1420–1431; doi:10.1038/bjp.2008.25; published online 18 February 2008
Physiology and pharmacology of alcohol: the imidazobenzodiazepine alcohol antagonist site on subtypes of GABAAreceptors as an opportunity for drug development?
Authors: Wallner M , Olsen R W
Published: February 2008

Alcohol (ethanol, EtOH) has pleiotropic actions and induces a number of acute and long‐term effects due to direct actions on alcohol targets, and effects of alcohol metabolites and metabolism. Many detrimental health consequences are due to EtOH metabolism and metabolites, in particular acetaldehyde, whose high reactivity leads to nonspecific chemical modifications of proteins and nucleic acids. Like acetaldehyde, alcohol has been widely considered a nonspecific drug, despite rather persuasive evidence implicating inhibitory GABAAreceptors (GABAARs) in acute alcohol actions, for example, a GABAAR ligand, the imidazobenzodiazepine Ro15‐4513 antagonizes many low‐to‐moderate dose alcohol actions in mammals. It was therefore rather surprising that abundant types of synaptic GABAARs are generally not responsive to relevant low concentrations of EtOH. In contrast, δ‐subunit‐containing GABAARs and extrasynaptic tonic GABA currents mediated by these receptors are sensitive to alcohol concentrations that are reached in blood and tissues during low‐to‐moderate alcohol consumption. We recently showed that low‐dose alcohol enhancement on highly alcohol‐sensitive GABAAR subtypes is antagonized by Ro15‐4513 in an apparently competitive manner, providing a molecular explanation for behavioural Ro15‐4513 alcohol antagonism. The identification of a Ro15‐4513/EtOH binding site on unique GABAAR subtypes opens the possibility to characterize this alcohol site(s) and screen for compounds that modulate the function of EtOH/Ro15‐4513‐sensitive GABAARs. The utility of such drugs might range from novel alcohol antagonists that might be useful in the emergency room, to drugs for the treatment of alcoholism, as well as alcohol‐mimetic drugs to harness acute positive effects of alcohol.

British Journal of Pharmacology(2008)154, 288–298; doi:10.1038/bjp.2008.32; published online 18 February 2008
A novel activity for substance P: stimulation of peroxisome proliferator‐activated receptor‐γ protein expression in human monocytes and macrophages
Authors: Amoruso A , Bardelli C , Gunella G , Ribichini F , Brunelleschi S
Published: February 2008

Background and purpose: Substance P (SP) and peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) play important roles in different inflammatory conditions and are both expressed in human monocytes and macrophages. However, it is not known whether or not they interact. This study was undertaken to evaluate the effects of SP on PPAR‐γ protein expression in monocytes and macrophages (MDMs: monocyte‐derived macrophages) from healthy smokers and non‐smokers.

Experimental approach: PPAR‐γ protein was detected by western blot and quantified by calculating the ratio between PPAR‐γ and β‐actin protein expression. Constitutive tachykinin NK1 receptor expression in monocytes and MDMs from healthy smokers and non‐smokers was evaluated by western blot. Cytokine release was evaluated by ELISA.

Key results: In the concentration range 10−10–10−6 M, SP stimulated PPAR‐γ protein expression in monocytes and MDMs, being more effective in cells from healthy smokers. Moreover, in these cells there was a constitutively increased expression of NK1 receptors. SP‐induced expression of the PPAR‐γ protein was receptor‐mediated, as it was reproduced by the NK1 selective agonist [Sar9Met(O2)11]SP and reversed by the competitive NK1 antagonist GR71251. SP‐induced maximal effects were similar to those evoked by 15‐deoxy‐Δ12,14‐prostaglandin J2; an endogenous PPAR‐γ agonist, and were significantly reduced by a PPAR‐γ antagonist. NK1 and PPAR‐γ agonists exerted opposite effects on TNF‐α release from monocytes and MDMs.

Conclusions and implications: Enhancement of PPAR‐γ protein expression represents a novel activity for SP, which could contribute to a range of chronic inflammatory disorders.
Molecular markers for the follow‐up of enzyme‐replacement therapy in mucopolysaccharidosis type VI disease
Authors: Natale Paola Di , Villani Guglielmo R. D. , Parini Rossella , Scarpa Maurizio , Parenti Giancarlo , Pontarelli Gianfranco , Grosso Michela , Sersale Giovanna , Tomanin Rosella , Sibilio Michelina , Barone Rita , Fiumara Agata
Published: February 2008

MPS VI (mucopolysaccharidosis type VI) is a lysosomal storage disease in which deficient activity of the enzyme N‐acetylgalactosamine 4‐sulfatase [ASB (arylsulfatase B)] impairs the stepwise degradation of the GAG (glycosaminoglycan) dermatan sulfate. Clinical studies of ERT (enzyme replacement therapy) by using rhASB (recombinant human ASB) have been reported with promising results. The release of GAG into the urine is currently used as a biomarker of disease, reflecting in some cases disease severity and in all cases therapeutic responsiveness. Using RNA studies in four Italian patients undergoing ERT, we observed that TNFα (tumour necrosis factor α) might be a biomarker for MPS VI responsive to therapy. In addition to its role as a potential biomarker, TNFα expression could provide insights into the possible pathophysiological mechanisms underlying the mucopolysaccharidoses.
Expression and purification of the 26 kDa periplasmic protein of Brucella abortus: a reagent for the diagnosis of bovine brucellosis
Authors: Kumar Sanjay , Tuteja Urmil , Kumar Ashok , Batra Harsh Vardhan
Published: February 2008

Development of a single diagnostic test for brucellosis in animals is the top priority of present‐day research in the field. There is currently a battery of serological tests relying mainly on the use of LPS (lipopolysaccharide) as an antigen, culminating in false positives due to serological cross‐reactivity. Other problems include difficulties in antigen production and the associated biohazard risk. This has prompted the need to develop an alternative antigen to replace LPS. In the present study, we cloned and expressed a BP26 (26 kDa periplasmic protein) antigen gene (bp26) of Brucella abortus. The recombinant periplasmic protein [rBP26 (recombinant BP26)] was expressed to high levels in Escherichia coli and purified in a single step. The purified rBP26 was examined for its binding activity with antibodies in a serum derived from a rabbit immunized intramuscularly with whole‐cell lysate of B. abortus, as well as with commercial Brucella antibody (Difco). The purified rBP26 was used to develop an in‐house plate ELISA and was further tested with a panel of 75 bovine brucellosis sera samples characterized previously by conventional serological tests. The results of both were in excellent agreement. The results show that rBP26 has potential use in the diagnosis of brucellosis, both in the laboratory and in field‐based conditions with high levels of sensitivity and specificity.
Expression of functional human (pro)renin receptor in silkworm (Bombyx mori) larvae using BmMNPV bacmid
Authors: Du Dongning , Kato Tatsuya , Nabi A. H. M. Nurun , Suzuki Fumiaki , Park Enoch Y.
Published: February 2008

The circulating RA (renin–angiotensin) system is essential for the regulation of blood pressure and electrolyte balance. Recently, plasma prorenin has been reported to significantly increase its level in diabetes and to be possibly non‐proteolytically activated by binding to the PRR [(pro)renin receptor] on the cell membrane reported in several tissues during circulation. Although many pathological aspects have been researched, there is a lack of sufficient information on the biochemical structure and biological function of this hPRR (human PRR) because of the difficulty in increasing hPRR expression. In the present study, GFPuv–hPRR (hPRR fused with green fluorescence protein when excited with long‐wave UV light) was successfully expressed by using BmMNPV (Bombyx mori multiple nucleopolyhedrovirus) bacmid DNA in silkworm (Bombyx mori) larvae. Some of the hPRR was expressed in the haemolymph of silkworm larvae and some of the hPRR was located in the fat body of silkworm larvae. The binding ability of hPRR expressed in the haemolymph and fat body with renin or prorenin was analysed by ELISA and surface plasmon resonance using a biosensor respectively. These binding assays suggest that the expressed hPRR has a functional bioactivity. hPRR preparation in silkworm larvae would, therefore, be useful for biochemical and biomedical researches related to PRR.
Sustainable Tourism Innovation: Challenging Basic Assumptions
Authors: Moscardo Gianna
Published: February 2008

Although much of the discussion of innovation focuses on new products and technologies, all innovation is based on challenging existing assumptions and ways of thinking. This paper argues that one option to develop new ways of thinking and innovation in tourism is to argue that there is no such thing as sustainable tourism. If we begin with the assumption that tourism cannot be sustainable in its own right but may contribute to the sustainable development of some regions under some circumstances, then a number of new approaches to tourism development emerge. In particular, it is argued that stronger links may emerge between tourism and other economic activities and development options. These potential synergies are described and illustrated with a range of examples. In addition, the paper sets out a series of additional criteria that could be used to evaluate different potential tourism developments and makes suggestions about the development of sustainability performance indicators. Finally, the paper highlights the importance of better knowledge management systems to support innovation in tourism.
Australian canola germplasm differs in nitrogen and sulfur efficiency
Authors: Balint Tatjana , Rengel Zdenko , Allen David
Published: February 2008

Eighty-four canola genotypes, including current commercial Australian genotypes, some older Australian genotypes, new breeding lines, and several genotypes from China, were screened for nitrogen and sulfur efficiency in the early growth stage. Plants were grown in a glasshouse using virgin brown Lancelin soil (Uc4.22) supplied with basal nutrients. The treatments were: (i) adequate nitrogen and sulfur, (ii) low nitrogen, and (iii) low sulfur. Canola shoots were harvested at 38 days after sowing when growth reduction and the nitrogen and sulfur deficiency symptoms were evident in most genotypes.
The nitrogen or sulfur efficiency in canola genotypes was evaluated on the basis of: (1) growth at low nitrogen or sulfur supply, (2) growth at low relative to adequate nitrogen and sulfur supply, and (3) nitrogen or sulfur utilisation efficiency expressed as shoot dry weight per unit of nitrogen or sulfur content in shoots.
Genotypic variation in growth and nitrogen or sulfur efficiency in canola germplasm was significant. Two genotypes (Chikuzen and 46C74) were ranked efficient and 2 inefficient (CBWA-005 and Beacon) in uptake and utilisation of nitrogen under all 3 criteria. In terms of sulfur efficiency, genotype Argentina was ranked efficient, whereas CBWA-003 and IB 1363 were classified inefficient under all 3 criteria. Two canola genotypes (Surpass 600 and 46C74) were both nitrogen- and sulfur-efficient in terms of relative growth at low v. adequate nutrition; their use in the breeding programs could be considered.
Variation in early phosphorus-uptake efficiency among wheat genotypes grown on two contrasting Australian soils
Authors: Liao Mingtan , Hocking Peter J. , Dong Bei , Delhaize Emmanuel , Richardson Alan E , Ryan Peter R.
Published: February 2008

Seedlings from 198 wheat genotypes were screened in glasshouse trials for early biomass production (49 days after sowing, DAS) in a soil high in total phosphorus (P) but low in plant-available P. Fifteen hexaploid bread wheats were then examined more closely for early biomass production on 2 low-P soils: a highly P-fixing Ferrosol (1.3 mg resin-extractable P/kg) and a Red Kandosol (5.2 mg resin-extractable P/kg). The soils were either unamended for P or supplemented with sufficient P for maximum growth. Single lines of rye, triticale, and durum wheat were included for comparison. The plants were harvested at 21 and 35 DAS, and shoot biomass, root biomass, P content, and root length were measured. Shoot biomass was correlated with the P content of the seed in both unamended soils at the first harvest but only in the Ferrosol at the second harvest. There were no correlations between seed P and shoot biomass in the high-P treatments at either harvest. Genotypes were compared with one another by plotting shoot biomass from the high-P treatment against shoot biomass from the low-P treatment. Phosphorus-efficient genotypes were defined as those with relatively greater biomass at low P, while genotypes with a high biomass potential were defined as those able to accumulate relatively more biomass at high P. Two hexaploid wheats, Kukri and Vigour 18, were ranked as being P-efficient genotypes with a high biomass potential on both soils, while Halberd, CD87, and Katepwa were P-inefficient on both soils. Biomass accumulation for each genotype was compared with their root biomass, root : shoot ratio, specific root length and P-uptake efficiency. The strongest correlation across all treatments occurred between shoot biomass and root biomass. We discuss factors that may contribute to the variation in P-uptake efficiency among the genotypes.
Persistence of diverse lucerne (Medicago sativa sspp.) germplasm under farmer management across a range of soil types in southern Australia
Authors: Humphries A. W. , Zhang X. G. , McDonald K. S. , Latta R. A. , Auricht G. C.
Published: February 2008

The persistence of a diverse group of lucerne (Medicago sativa sspp.) germplasm was evaluated under farmer management across a range of acidic and neutral-alkaline soils at 8 sites in South and Western Australia. Dryland field trials were sown in parallel with commercial lucerne paddocks being grown in rotation with cereal crops, remaining unfenced and under management by the farmer for the life of the stand. The combined differences in soil type, grazing management, and low rainfall contributed to large differences in average lucerne persistence between sites in South Australia and Western Australia. After 3 years, plant frequency (a measure of plant density used to monitor persistence) averaged 17% (at least 17 plants/m2) on the strongly acidic soils in Western Australia and 30% on the neutral-alkaline soils in South Australia (at least 30 plants/m2). Differences in persistence were attributed to the combined stresses of soil pH, drought conditions, and grazing management. Genetic correlation analyses between sites failed to show any clear patterns in the performance of entries at each site, except for a high correlation between 2 South Australian sites in close proximity. Highly winter-active germplasm was less persistent than other winter activity groups, but was higher yielding when assessed in an additional trial at Katanning, WA. Highly winter-active lucerne (class 9–10) should continue to be recommended for short (2–4 year) phases in rotation with cereals, and winter-active groups (6–8) should be recommend for longer (4–7 year) phases in rotations. The results of this evaluation are also being used to identify broadly adapted, elite genotypes in the breeding of new lucerne cultivars for the southern Australian cropping districts.
Morphology of young sugarcane stalks produced at different stages of crop development
Authors: Salter B. , Bonnett G. D. , Lawn R. J.
Published: February 2008

Sugarcane suckers are tillers that appear late in crop development. They dilute the sucrose content of the harvested cane at the mill, reducing grower profitability. Suckers appear to have different morphology from other sugarcane stalks. Experiments were established to quantify some of these morphological differences, to determine whether these differences were conserved across a vegetatively propagated generation, and to investigate the influence of the mature stalk to which the sucker is attached on sucker morphology. Experiments were established in northern Queensland, Australia, using cvv. Q117, Q138, and Q152 to compare suckers with young primary stalks in a plant crop and/or young ratoon stalks. Leaf lamina length, breadth, area, height to last fully expanded leaf, internode diameter, and growth measurements were taken. Suckers had broader leaves, resulting in a smaller leaf length/breadth ratio, longer leaf sheaths, and lower specific leaf area at least for the first 3 leaves. Sucker stalks were thicker than normal stalks. Sucker growth was highly variable, but some were able to outgrow young primary stalks in a plant crop. When mature stalks, to which suckers were attached, were removed, the leaves produced by suckers were more similar to leaves on normal stalks with larger length/breadth ratio. The morphological differences were not carried over into plants arising from the buds on suckers. Although the reasons for these morphological differences are unknown, it is likely that the transfer of some factor(s) from the stalks to which suckers are attached, and/or an altered light environment within the canopy, may contribute to the morphology of sucker shoots.
Equilibrium studies, synthesis and characterisation of zwitterionic buffer (HEPES and HEPPS) dimethyltin(IV) complexes
Authors: Mohamed Mahmoud M.A.
Published: February 2008

The interaction of the dimethyltin(IV) dication (DMT) with some selected buffers “Good’s buffer”, such as HEPES and HEPPS (LH2+) were investigated using a potentiometric technique. The stepwise formation constants of the complexes formed in solution were calculated using the non-linear least-square program MINIQUAD-75. The concentration distribution of the various complex species was evaluated as a function of pH. The effect of dioxane as a solvent on the protonation constants of ligands and the formation constants of dimethyltin(IV) complexes were discussed. The thermodynamic parameters ΔH° and ΔS° calculated from the temperature dependence of the equilibrium constants were investigated. The bonding sites of the dimethyltin(IV) complexes in solid state with HEPES and HEPPS were characterised by means of elemental analyses and FTIR. The NMR (1H, 13C) spectra of the DMT-HEPES complex indicate a strongly distorted octahedral geometry around the tin atom. Thermal analyses (TGA and DTA) are also discussed. Thermodynamic parameters, such as activation energy (Ea), pre-exponential factor (A), entropy of activation (ΔS*) and free energy of activation (ΔG*) have been calculated for each step, employing the integral method of Coats and Redfern. The reaction enthalpy (ΔH) is obtained from DTA data.
Bi(V) organic framework in an asymmetric system: Synthesis, spectroscopic, XRPD and molecular modeling
Authors: Kumar Rajiv , Mishra P.
Published: February 2008

The bismuth organic framework of 5-(2,4-diguanidino-3,5,6-trihydroxy-cyclohexoxy)-4-[4,5-dihydroxy-6-(hydroxymethyl)-3-methylamine-tetrahydrop-ya-2-yl] oxy-3-hydroxy-2-methyltetrahydrofuran-3-carbaldehyde and (2S,5R,6R)-6-[(8)-2-amino-2-phenylacetamido]-3,3-dimethyl-t-oxo-4-thia-1azabicyclo [3.2.0] heptane-2-carboxylic acid (L) is reported. All the conformational changes and the binding abilities of the organic framework toward Bi(V) were identified by various physiochemical and spectroscopic measurements including IR, 1H NMR, UV – vis, mass spectroscopy, molecular modeling and X-ray powder diffractometry. The bond formation between Bi(V) and the donor atoms of the ligand, nitrogen and oxygen, have been investigated. Molecular modeling of the complex was also used to elucidate the coordination environment and molecular arrangement along with bond lengths and angles.
Study of adsorption of acid dye from aqueous solutions using bentonite
Authors: Hashemian Saeedeh
Published: February 2008

The removal of the dye cyanine acid blue (CAB) with bentonite clay was studied. The effect of various experimental parameters was investigated using a batch adsorption technique. Saturated sodium chloride treatment results in an increase in adsorption capacity of bentonite. A pH value of 2 is favorable for the adsorption of CAB. The maximum removal of CAB is obtained at a dosage of 2 g of bentonite. The use of Fe+3 ion (2.0 × 10−3 M) as a catalyst increased the percentage of dye removal. It was found that the Freundlich isotherm appears to fit the isotherm data better than the Langmuir isotherm. A fast adsorption rate was observed and could be well-described by a pseudo-second-order kinetics model.
Spectroscopic characterization of complexes of tetracycline with cobalt(II), nickel(II), cadmium(II) and inorganic Sn(II)
Authors: Mishra Parashuram , Singh Bibhesh K. , Dhingra Shuchi , Sharma Rakesh K.
Published: February 2008

Complexes of Co(II), Ni(II), Cd(II) and inorganic Sn(II) with tetracycline (TC) have been synthesized and characterized by elemental analyses, vibrational spectra, electronic spectra, 1H NMR spectra, magnetic susceptibility measurement, thermal studies and X-ray powder diffraction studies. TC forms a 1:1 complex with the metal ions through the oxygen of the hydroxyl group at the A ring and the carbonyl oxygen atom of the amide group in coordination. The results of spectral techniques and magnetic susceptibility measurement correlate well. Kinetic and thermodynamic parameters were computed from the thermal data using the Coats and Redfern method, which confirm first order kinetics. X-ray powder diffraction data determined the cell parameters of the complexes. The molecular structures of the complexes have been optimized by MM2 calculations and supported square planar/tetrahedral geometry around Metal (II) ions.
Synthesis, structure, and redox properties of copper(I) complexes with phenylpyridin-2-ylmethyleneamine derivatives
Authors: Dehghanpour Saeed , Mahmoudi Ali
Published: February 2008

Four copper(I) complexes, [Cu(diimine)2]ClO4 (1 – 4, Diimine=(4-fluorophenyl)pyridin-2-ylmethylene-amine, (1) (4-chlorophenyl)pyridin-2-ylmethyleneamine, (2), (4-bromophenyl)pyridin-2-ylmethyleneamine, (3), and (4-iodophenyl)pyridin-2-ylmethyleneamine, (4)) have been synthesized and characterized by CHN analyses, 1H NMR, IR, and UV – vis spectroscopy. The crystal structure of [Cu(B)2]ClO4 (2) was determined from single crystal X-ray diffraction. The coordination polyhedron about the copper(I) center in 2 is best described as a distorted tetrahedron. A quasi-reversible redox behavior is observed for the complexes. The spectral, structural, and redox data of these complexes are compared with similar iminopyridine copper(I) complexes. The variation of substituent on the phenyl ring of iminopyridine ligands did not show significant change in the absorption and redox properties of these types of complexes.
Growth standards for nine North American fish species
Authors: JACKSON Z. J. , QUIST M. C. , LARSCHEID J. G.
Published: February 2008

Abstract  Standard methods for comparing population characteristics within and among fish populations greatly enhance communications among fisheries scientists, improve the efficiency of data analysis, and provide insight that helps guide management actions. Although standard methods are available for comparing some fish population characteristics (e.g. length structure, body condition), similar methods are lacking for comparing growth. The purpose of this study was to provide standards (i.e. percentiles and a standard growth model) for nine ecologically and recreationally important fish species. Percentile distributions of mean back‐calculated length at age were estimated using data obtained from the published literature and from data solicited from state and federal agencies throughout North America. Percentiles of growth were estimated for bluegill, Lepomis macrochirus Rafinesque, common carp, Cyprinus carpio Linnaeus, flathead catfish, Pylodictis olivaris (Rafinesque), largemouth bass, Micropterus salmoides (Lacepède), sauger, Sander canadensis (Griffith & Smith), smallmouth bass, Micropterus dolomieu Lacepède, white bass, Morone chrysops (Rafinesque) and yellow perch, Perca flavescens (Mitchill). Standard growth models (i.e. von Bertalanffy models) were developed for these species and for channel catfish, Ictalurus punctatus (Rafinesque). These results provide tools that will help scientists compare growth of fishes across North America.
Detrimental role of endogenous nitric oxide in host defence against Sporothrix schenckii
Authors: Fernandes Karla Simone S. , Neto Edward Helal , Brito Marcelly M. S. , Silva João S. , Cunha Fernando Q. , Barja‐Fidalgo Christina
Published: February 2008

We earlier demonstrated that nitric oxide (NO) is a fungicidal molecule against Sporothrix schenckii in vitro. In the present study we used mice deficient in inducible nitric oxide synthase (iNOS–/–) and C57BL/6 wild‐type (WT) mice treated with Nω‐nitro‐arginine (Nitro‐Arg‐treated mice), an NOS inhibitor, both defective in the production of reactive nitrogen intermediates, to investigate the role of endogenous NO during systemic sporotrichosis. When inoculated with yeast cells of S. schenckii, WT mice presented T‐cell suppression and high tissue fungal dissemination, succumbing to infection. Furthermore, susceptibility of mice seems to be related to apoptosis and high interleukin‐10 and tumour necrosis factor‐α production by spleen cells. In addition, fungicidal activity and NO production by interferon‐γ (IFN‐γ) and lipopolysaccharide‐activated macrophages from WT mice were abolished after fungal infection. Strikingly, iNOS–/– and Nitro‐Arg‐treated mice presented fungal resistance, controlling fungal load in tissues and restoring T‐cell activity, as well as producing high amounts of IFN‐γ Interestingly, macrophages from these groups of mice presented fungicidal activity after in vitro stimulation with higher doses of IFN‐γ. Herein, these results suggest that although NO was an essential mediator to the in vitro killing of S. schenckii by macrophages, the activation of NO system in vivo contributes to the immunosuppression and cytokine balance during early phases of infection with S. schenckii.
Soluble CD276 (B7‐H3) is released from monocytes, dendritic cells and activated T cells and is detectable in normal human serum
Authors: Zhang Guangbo , Hou Jianquan , Shi Jinfang , Yu Gehua , Lu Binfeng , Zhang Xueguang
Published: February 2008

Expression of membrane CD276 (mB7‐H3) has been reported on dendritic cells (DCs), monocytes, activated T cells, and various carcinoma cells. However, reports concerning its in vivo function have been inconsistent. Moreover, whether there is a soluble form of this protein is not known. In this study, using a sensitive dual monoclonal antibody sandwich enzyme‐linked immunosorbent assay (ELISA) to detect the soluble form of B7‐H3 (sB7‐H3), we demonstrated the release of sB7‐H3 by monocytes, DCs, activated T cells, and various mB7‐H3+ but not mB7‐H3– carcinoma cells. Release from cells was blocked by addition of a matrix metalloproteinase inhibitor (MMPI), which concomitantly caused the accumulation of B7‐H3 on the cell surface. To determine the level of circulating sB7‐H3, more than 200 serum samples were included in the study. The results indicated that sB7‐H3 was present at high levels in all serum samples. Western blotting of sB7‐H3 from cell culture supernatants or sera of healthy donors indicated that the molecular size was approximately 16 kDa. Soluble B7‐H3 was able to bind to the B7‐H3 receptor (B7‐H3R) on activated T cells, which showed that sB7‐H3 is a functionally active form. These results indicate that release of sB7‐H3 from the cell surface is mediated by a matrix metalloproteinase and probably regulates B7‐H3R/B7‐H3 interactions in vivo. Cleavage of sB7‐H3 to an active soluble form would alter both proximal and distal cellular responses.
Dissecting innate immunity by germline mutagenesis
Authors: Rutschmann Sophie , Hoebe Kasper
Published: February 2008

The innate arm of our immune system is the first line of defence against infections. In addition, it is believed to drive adaptive immune responses, which help fight pathogens and provide long‐term memory. As such, the innate immune system is instrumental for protection against pathogens that would otherwise destroy their host. Although our understanding of the innate immune components involved in pathogen sensing and fighting is improving, it is still limited. This is particularly exemplified by increased documentation of innate immune deficiencies in humans that often result in high and recurrent susceptibility to infections or even death, without the genetic cause being evident. To provide further insight into the mechanisms by which pathogen sensing and eradication occur, several strategies can be used. The current review focuses on the forward genetic approaches that have been used to dissect innate immunity in the fruit fly and the mouse. For both animal models, forward genetics has been instrumental in the deciphering of innate immunity and has greatly improved our understanding of how we respond to invading pathogens.