bluuebunny/crossref_metadata_2025 huggingface dataset:
Doramectin toxicity in a group of lions (Panthera leo)
Authors: Lobetti Remo G. , Caldwell Peter
Published: October 2012

Ten lions (Panthera leo) that were treated with a single injection of doramectin at a dose ranging between 0.2 mg/kg and 0.5 mg/kg showed clinical signs consistent with avermectin toxicity, namely ataxia, hallucinations, and mydriasis. Two subsequently died whereas the other eight lions recovered after 4–5 days with symptomatic therapy. Post-mortem examinations of the two that died showed cyanosis, severe pulmonary oedema, pleural effusion, and pericardial effusion, with histopathology not revealing any abnormalities. In both these lions, doramectin brain and liver tissue concentrations were elevated. Although doramectin is regularly used in wild felids, to date there have been no reports of avermectin toxicity in the literature. This article highlights the potential for doramectin toxicity in this species.
Knowledge Building Insights on Biomarkers of Arsenic Toxicity to Keratinocytes and Melanocytes
Authors: Isokpehi Raphael D. , Udensi Udensi K. , Anyanwu Matthew N. , Mbah Andreas N. , Johnson Matilda O. , Edusei Kafui , Bauer Michael A. , Hall Roger A. , Awofolu Omotayo R.
Published: October 2012

Exposure to inorganic arsenic induces skin cancer and abnormal pigmentation in susceptible humans. High-throughput gene transcription assays such as DNA microarrays allow for the identification of biological pathways affected by arsenic that lead to initiation and progression of skin cancer and abnormal pigmentation. The overall purpose of the reported research was to determine knowledge building insights on biomarker genes for arsenic toxicity to human epidermal cells by integrating a collection of gene lists annotated with biological information. The information sets included toxicogenomics gene-chemical interaction; enzymes encoded in the human genome; enriched biological information associated with genes; environmentally relevant gene sequence variation; and effects of non-synonymous single nucleotide polymorphisms (SNPs) on protein function. Molecular network construction for arsenic upregulated genes TNFSF18 (tumor necrosis factor [ligand] superfamily member 18) and IL1R2 (interleukin 1 Receptor, type 2) revealed subnetwork interconnections to E2F4, an oncogenic transcription factor, predominantly expressed at the onset of keratinocyte differentiation. Visual analytics integration of gene information sources helped identify RAC1, a GTP binding protein, and TFRC, an iron uptake protein as prioritized arsenic-perturbed protein targets for biological processes leading to skin hyperpigmentation. RAC1 regulates the formation of dendrites that transfer melanin from melanocytes to neighboring keratinocytes. Increased melanocyte den-dricity is correlated with hyperpigmentation. TFRC is a key determinant of the amount and location of iron in the epidermis. Aberrant TFRC expression could impair cutaneous iron metabolism leading to abnormal pigmentation seen in some humans exposed to arsenicals. The reported findings contribute to insights on how arsenic could impair the function of genes and biological pathways in epidermal cells. Finally, we developed visual analytics resources to facilitate further exploration of the information and knowledge building insights on arsenic toxicity to human epidermal keratinocytes and melanocytes.
Proton Pump Inhibitor use in Hospitalized Patients: Is Overutilization Becoming a Problem?
Authors: Durand Cheryl , Willett Kristine C. , Desilets Alicia R.
Published: October 2012

Proton pump inhibitors (PPIs) are among the most common classes of medications prescribed. Though they were previously thought of as safe, recent literature has shown risks associated with their use including increased risk for Clostridium difficile infection, pneumonia, and fractures. Due to these risks, it is important to determine if PPIs are being used appropriately. This review evaluates seven studies in hospitalized patients. Additionally, this review evaluates literature pertaining to recently discovered adverse reactions; all studies found PPIs are being overutilized. Findings highlight the importance of evaluating appropriate therapy with these agents and recommending discontinuation if a proper indication does not exist.
Characterization of Intra-myocellular Lipids Using 2d Localized Correlated Spectroscopy and Abdominal Fat Using Mri in Type 2 Diabetes
Authors: Srikanthan Preethi , Singhal Aparna , Lee Cathy C. , Nagarajan Rajakumar , Wilson Neil , Roberts Christian K. , Hahn Theodore J. , Thomas M. Albert
Published: October 2012

A major goal of this pilot study was to quantify intramyocellular lipids (IMCL), extra-myocellular lipids (EMCL), unsaturation index (UI) and metabolites such as creatine (Cr), choline (Ch) and carnosine (Car), in the soleus muscle using two-dimensional (2D) localized correlated spectroscopy (L-COSY). Ten subjects with type 2 diabetes (T2D), controlled by lifestyle management alone, and 9 healthy control subjects, were studied. In T2D patients only, the following measurements were obtained: body mass index (BMI); waist circumference (WC); abdominal visceral and subcutaneous fat quantified using breath-held magnetic resonance imaging (MRI); a fasting blood draw for assessment of glucose, insulin, and estimation of homeostasis model assessment of insulin resistance (HOMA-IR), HbA1c, and high-sensitivity c-reactive protein (hs-CRP). Analysis of the soleus muscle 2D L-COSY spectral data showed significantly elevated IMCL ratios with respect to Cr and decreased IMCL UI in T2D when compared to healthy subjects ( P < 0.05). In T2D subjects, Pearson correlation analysis showed a positive correlation of IMCL/Cr with EMCL/Cr (0.679, P < 0.05) and HOMA-IR (0.633, P < 0.05), and a non-significant correlation of visceral and subcutaneous fat with magnetic resonance spectroscopy (MRS) and other metrics. Characterization of muscle IMCL and EMCL ratios, UI, and abdominal fat, may be useful for the noninvasive assessment of the role of altered lipid metabolism in the pathophysiology of T2D, and for assessment of the effects of future therapeutic interventions designed to alter metabolic dysfunction in T2D.
On dithiothreitol (DTT) as a measure of oxidative potential for ambient particles: evidence for the importance of soluble transition metals
Authors: Charrier J. G. , Anastasio C.
Published: October 2012

Abstract. The rate of consumption of dithiothreitol (DTT) is increasingly used to measure the oxidative potential of particulate matter (PM), which has been linked to the adverse health effects of PM. While several quinones are known to be very reactive in the DTT assay, it is unclear what other chemical species might contribute to the loss of DTT in PM extracts. To address this question, we quantify the rate of DTT loss from individual redox-active species that are common in ambient particulate matter. While most past research has indicated that the DTT assay is not sensitive to metals, our results show that seven out of the ten transition metals tested do oxidize DTT, as do three out of the five quinones tested. While metals are less efficient at oxidizing DTT compared to the most reactive quinones, concentrations of soluble transition metals in fine particulate matter are generally much higher than those of quinones. The net result is that metals appear to dominate the DTT response for typical ambient PM2.5 samples. Based on particulate concentrations of quinones and soluble metals from the literature, and our measured DTT responses for these species, we estimate that for typical PM2.5 samples approximately 80% of DTT loss is from transition metals (especially copper and manganese), while quinones account for approximately 20%. We find a similar result for DTT loss measured in a small set of PM2.5 samples from the San Joaquin Valley of California. Because of the important contribution from metals, we also tested how the DTT assay is affected by EDTA, a chelator that is sometimes used in the assay. EDTA significantly suppresses the response from both metals and quinones; we therefore recommend that EDTA should not be included in the DTT assay.
On the interpretation of an unusual in-situ measured ice crystal scattering phase function
Authors: Baran A. J. , Gayet J.-F. , Shcherbakov V.
Published: October 2012

Abstract. In-situ Polar Nephelometer (PN) measurements of unusual ice crystal scattering phase functions, obtained near the cloud-top of a mid-latitude anvil cloud, at a temperature of about −58 °C, were recently reported by Gayet et al. (2012). The ice crystal habits that produced the phase functions consisted of aggregates of ice crystals and aggregates of quasi-spherical ice particles. The diameters of the individual quasi-spherical ice particles were estimated to be between about 15 μm and 20 μm. The measured-averaged scattering phase functions were featureless, at scattering angles less than about 100°, but an ice bow-like feature was noted between the scattering angles of about 120° to 160°. The estimated asymmetry parameter was 0.78 ± 0.04. In this paper, the averaged scattering phase function is interpreted in terms of a weighted habit mixture model. The model that provides the best overall fit to the measured scattering phase function comprises of highly distorted ten-element hexagonal ice aggregates and quasi-spherical ice particles. The smaller quasi-spherical ice crystals are represented by Chebyshev ice particles of order 3, and were assumed to have equivalent spherical diameters of 24 μm. The asymmetry parameter of the best overall model was found to be 0.79. It is argued that the Chebyshev-like ice particles are responsible for the ice bow-like feature and mostly dominate the scattered intensity measured by the PN. The results from this paper have important implications for climate modelling (energy balance of anvils), cloud physics and the remote sensing of cirrus properties.
The challenge to NOx emission control for heavy-duty diesel vehicles in China
Authors: Wu Y. , Zhang S. J. , Li M. L. , Ge Y. S. , Shu J. W. , Zhou Y. , Xu Y. Y. , Hu J. N. , Liu H. , Fu L. X. , He K. B. , Hao J. M.
Published: October 2012

Abstract. China's new "Twelfth Five-Year Plan" set a target for total NOx emission reduction of 10% for the period of 2011–2015. Heavy-duty diesel vehicles (HDDVs) have been considered a major contributor to NOx emissions in China. Beijing initiated a comprehensive vehicle test program in 2008. This program included a sub-task for measuring on-road emission profiles of hundreds of HDDVs using portable emission measurement systems (PEMS). The major finding is that neither the on-road distance-specific (g km−1) nor brake-specific (g kWh−1) NOx emission factors for diesel buses and heavy-duty diesel trucks improved in most cases as emission standards became more stringent. For example, the average NOx emission factors for Euro II, Euro III and Euro IV buses are 11.3 ± 3.3 g km−1, 12.5 ± 1.3 g km−1, and 11.8 ± 2.0 g km−1, respectively. No statistically significant difference in NOx emission factors was observed between Euro II and III buses. Even for Euro IV buses equipped with SCR systems, the NOx emission factors are similar to Euro III buses. The data regarding real-time engine performance of Euro IV buses suggest the engine certification cycles did not reflect their real-world operating conditions. These new on-road test results indicate that previous estimates of total NOx emissions for HDDV fleet may be significantly underestimated. The new estimate in total NOx emissions for the Beijing HDDV fleet in 2009 is 37.0 Gg, an increase of 45% compared to the previous study. Further, we estimate that the total NOx emissions for the national HDDV fleet in 2009 are approximately 4.0 Tg, higher by 1.0 Tg (equivalent to 18% of total NOx emissions for vehicle fleet in 2009) than that estimated in the official report. This would also result in 4% increase in estimation of national anthropogenic NOx emissions. More effective control measures (such as promotion of CNG buses and a new in-use compliance testing program) are urged to secure the goal of total NOx mitigation for the HDDV fleet in the future.
Contrasting trends of mass and optical properties of aerosols over the Northern Hemisphere from 1992 to 2011
Authors: Wang K. C. , Dickinson R. E. , Su L. , Trenberth K. E.
Published: October 2012

Abstract. Atmospheric aerosols affect both human health and climate. PMX is the mass concentration of aerosol particles that have aerodynamic diameters less than X μm, PM10 was initially selected to measure the environmental impact of aerosols. Recently, it was realized that fine particles are more hazardous than larger ones and should be measured. Consequently, observational data for PM2.5 have been obtained but only for a much shorter period than that of PM10. Optical extinction of aerosols, the inverse of meteorological visibility, is sensitive to particles less than 1.0 μm. These fine particles only account for a small part of total mass of aerosols although they are very efficient in light extinction. Comparisons are made between PM10 and PM2.5 over the period when the latter is available and with visibility data for a longer period. PM10 has decreased by 44% in Europe from 1992 to 2009, 33% in the US from 1993 to 2010, 10% in Canada from 1994 to 2009, and 26% in China from 2000 to 2011. However, in contrast, aerosol optical extinction has increased 7% in the US, 10% in Canada, and 18% in China during the above study periods. The reduction of optical extinction over Europe of 5% is also much less than the 44% reduction in PM10. Over its short period of record PM2.5 decreased less than PM10. Hence, PM10 is neither a good measure of changes in smaller particles nor of their long-term trends, a result that has important implications for both climate impact and human health effects. The increased fraction of anthropogenic aerosol emission, such as from vehicle exhaust, to total atmospheric aerosols partly explains this contrasting trend of optical and mass properties of aerosols.
Dynamics of the chemical composition of rainwater throughout Hurricane Irene
Authors: Mullaugh K. M. , Willey J. D. , Kieber R. J. , Mead R. N. ,   G. B. Avery Jr.
Published: October 2012

Abstract. Sequential sampling of rainwater from Hurricane Irene was carried out in Wilmington, NC, USA on 26 and 27 August 2011. Eleven samples were analyzed for pH, major ions (Cl−, NO3−, SO42−, Na+, K+, Mg2+, Ca2+, NH4+), dissolved organic carbon (DOC) and hydrogen peroxide (H2O2). Hurricane Irene contributed 16% of the total rainwater and 18% of the total chloride wet deposition received in Wilmington NC during all of 2011. This work highlights the main physical factors influencing the chemical composition of tropical storm rainwater: wind speed, wind direction, air mass back trajectory and vertical mixing, time of day and total rain volume. Samples collected early in the storm, when winds blew out of the east, contained dissolved components indicative of marine sources (salts from sea spray and low DOC). The seasalt components in the samples had two maxima in concentration during the storm the first of which occurred before the volume of rain had sufficiently washed out seasalt from the atmosphere and the second when the air mass dipped to low elevations over the Atlantic Ocean followed by rapid vertical mixing. As the storm progressed and winds shifted to a westerly direction, the chemical composition of the rainwater became characteristic of terrestrial storms (high DOC and NH4+ and low seasalt). This work demonstrates that tropical storms are not only responsible for significant wet deposition of marine components to land, but terrestrial components can also become entrained in rainwater, which can then be delivered to coastal waters via wet deposition. This study also underscores why analysis of one composite sample can lead to an incomplete interpretation of the factors that influence the chemically divergent analytes in rainwater during extreme weather events.
Technical Note: New methodology for measuring viscosities in small volumes characteristic of environmental chamber particle samples
Authors: Renbaum-Wolff L. , Grayson J. W. , Bertram A. K.
Published: October 2012

Abstract. Herein, a method for the determination of viscosities of small sample volumes is introduced, with important implications for the viscosity determination of particle samples from environmental chambers (used to simulate atmospheric conditions). The amount of sample needed is < 1 μl, and the technique is capable of determining viscosities (η) ranging between 10−3 and 103 Pascal seconds (Pa s) in samples that cover a range of chemical properties and with real-time relative humidity and temperature control; hence, the technique should be well-suited for determining the viscosities, under atmospherically relevant conditions, of particles collected from environmental chambers. In this technique, supermicron particles are first deposited on an inert hydrophobic substrate. Then, insoluble beads (~1 μm in diameter) are embedded in the particles. Next, a flow of gas is introduced over the particles, which generates a shear stress on the particle surfaces. The sample responds to this shear stress by generating internal circulations, which are quantified with an optical microscope by monitoring the movement of the beads. The rate of internal circulation is shown to be a function of particle viscosity but independent of the particle material for a wide range of organic and organic-water samples. A calibration curve is constructed from the experimental data that relates the rate of internal circulation to particle viscosity, and this calibration curve is successfully used to predict viscosities in multicomponent organic mixtures.
Application of the Statistical Oxidation Model (SOM) to secondary organic aerosol formation from photooxidation of C12 Alkanes
Authors: Cappa C. D. , Zhang X. , Loza C. L. , Craven J. S. , Yee L. D. , Seinfeld J. H.
Published: October 2012

Abstract. Laboratory chamber experiments are the main source of data on the mechanism of oxidation and the secondary organic aerosol (SOA) forming potential of volatile organic compounds. Traditional methods of representing the SOA formation potential of an organic do not fully capture the dynamic, multi-generational nature of the SOA formation process. We apply the Statistical Oxidation Model (SOM) of Cappa and Wilson (2012) to model the formation of SOA from the formation of the four C12 alkanes, dodecane, 2-methyl undecane, cyclododecane and hexylcyclohexane, under both high- and low-NOx conditions, based upon data from the Caltech chambers. In the SOM, the evolution of reaction products is defined by the number of carbon (NC) and oxygen (NO) atoms, and the model parameters are (1) the number of oxygen atoms added per reaction, (2) the decrease in volatility upon addition of an oxygen atom and (3) the probability that a given reaction leads to fragmentation of the molecules. Optimal fitting of the model to chamber data is carried out using the measured SOA mass concentration and the aerosol O : C atomic ratio. The use of the kinetic, multi-generational SOM is shown to provide insights into the SOA formation process and to offer promise for application to the extensive library of existing SOA chamber experiments that is available.
Cajander larch (Larix cajanderi) biomass distribution, fire regime and post-fire recovery in northeastern Siberia
Authors: Berner L. T. , Beck P. S. A. , Loranty M. M. , Alexander H. D. , Mack M. C. , Goetz S. J.
Published: October 2012

Abstract. Climate change and land-use activities are increasing fire activity across much of the Siberian boreal forest, yet the climate feedbacks from forest disturbances remain difficult to quantify due to limited information on forest biomass distribution, disturbance regimes and post-disturbance ecosystem recovery. Our primary objective here was to analyse post-fire accumulation of Cajander larch (Larix cajanderi Mayr.) aboveground biomass for a 100 000 km2 area of open forest in far northeastern Siberia. In addition to examining effects of fire size and topography on post-fire larch aboveground biomass, we assessed regional fire rotation and density, as well as performance of burned area maps generated from MODIS satellite imagery. Using Landsat imagery, we mapped 116 fire scar perimeters that dated c. 1966–2007. We then mapped larch aboveground biomass by linking field biomass measurements to tree shadows mapped synergistically from WorldView-1 and Landsat 5 satellite imagery. Larch aboveground biomass tended to be low during early succession (≤ 25 yr, 271 ± 26 g m−2, n = 66 [mean ± SE]) and decreased with increasing elevation and northwardly aspect. Larch aboveground biomass tended to be higher during mid-succession (33–38 yr, 746 ± 100 g m−2, n = 32), though was highly variable. The high variability was not associated with topography and potentially reflected differences in post-fire density of tree regrowth. Neither fire size nor latitude were significant predictors of post-fire larch aboveground biomass. Fire activity was considerably higher in the Kolyma Mountains (fire rotation = 110 yr, fire density = 1.0 ± 1.0 fires yr−1 × 104 km−2) than along the forest-tundra border (fire rotation = 792 yr, fire density = 0.3 ± 0.3 fires yr−1 × 104 km−2). The MODIS burned area maps underestimated the total area burned in this region from 2000–2007 by 40%. Tree shadows mapped jointly using high and medium resolution satellite imagery were strongly associated (r2 ≈ 0.9) with field measurements of forest structure, which permitted spatial extrapolation of aboveground biomass to a regional extent. Better understanding of forest biomass distribution, disturbances and post-disturbance recovery is needed to improve predictions of the net climatic feedbacks associated with landscape-scale forest disturbances in northern Eurasia.
Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy-covariance, biometric and continuous soil chamber measurements
Authors: Zanotelli D. , Montagnani L. , Manca G. , Tagliavini M.
Published: October 2012

Abstract. Carbon use efficiency (CUE) is a functional parameter that could possibly link the current increasingly accurate global estimates of gross primary production with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, net primary production (NPP) and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a~measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross-check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard both net ecosystem production and gross primary production on yearly basis, 380 ± 30 g C m−2 and 1263 ± 189 g C m−2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruits: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.09, was higher than the previously suggested constant values of 0.47–0.50. Low nitrogen investment in fruits, the limited root-apparatus, and the optimal growth temperature and nutritional condition observed at the site are suggested to be explanatory variables for the high CUE observed.
The relative importance of decomposition and transport mechanisms in accounting for C profiles
Authors: Guenet B. , Eglin T. , Vasilyeva N. , Peylin P. , Ciais P. , Chenu C.
Published: October 2012

Abstract. Soil is the major terrestrial reservoirs of carbon, and a substantial part of this carbon is stored in deep layers, typically deeper than 50 cm below the surface. Several studies underlined the quantitative importance of this deep Soil Organic Carbon (SOC) pool and models are needed to better understand this stock and its evolution under climate and land-uses changes. In this study, we test and compare 3 simple theoretical models of vertical transport for SOC against SOC profiles measurements from a long-term bare fallow experiment carried out by the Central-Chernozem State Natural Biosphere Reserve named after V.V. Alekhin, in the Kursk Region of Russia. The transport schemes tested are diffusion, advection or both diffusion and advection. They are coupled to two different formulations of soil carbon decomposition kinetics. The first formulation is a first order kinetics widely used in global SOC decomposition models; the second one links SOC decomposition rate to the amount of fresh organic matter, representing a "priming effect". Field data are from a set of three bare fallow plots where soil received no input during the past 20, 26 and 58 yr respectively. Parameters of the models were optimized using a Bayesian method. The best results are obtained when SOC decomposition is assumed to be controlled by fresh organic matter. In comparison to the first-order kinetic model, the "priming" model reduces the underestimation of SOC decomposition in the top layers and the over estimation in the deep layers. We also observe that the transport scheme that improved the fit with the data depends on the soil carbon mineralization formulation chosen. When soil carbon decomposition is modelled to depend on the fresh organic matter amount, the transport mechanisms which improves best the fit to the SOC profile data is the model representing both advection and diffusion. Interestingly, the older the bare fallow is, the lesser the need for diffusion is. This suggests that stabilized carbon may not be transported within the profile by the same mechanisms than more labile carbon.
Pathway of CH4 production, fraction of CH4 oxidized, and 13C isotope fractionation in a straw incorporated rice field
Authors: Zhang G. B. , Ji Y. , Ma J. , Liu G. , Xu H. , Yagi K.
Published: October 2012

Abstract. Straw incorporation generally increases CH4 emission from rice fields, but its effects on the mechanism of CH4 emission, especially on the pathway of CH4 production and the fraction of CH4 oxidized are not well known. To investigate the methanogenic pathway, the fraction of CH4 oxidized as well as the stable carbon isotope fractionation during the oxidation and transport of CH4 as affected by straw incorporation, production and oxidation of CH4 in paddy soil and rice roots and δ13C-values of produced CH4 and CO2, and emitted CH4 were observed in incubation and field experiments. Straw incorporation significantly enhanced CH4 production potentials of the paddy soil and rice roots. However, it increased the relative contribution of acetate to total CH4 production (Fac) in the paddy soil by ~ 10–30%, but decreased Fac-value of the rice roots by ~ 5–20%. Compared with rice roots, paddy soil was more important in acetoclastic methanogenesis, with Fac-value being 6–30% higher. Straw incorporation highly decreased the fraction of CH4 oxidized (Fox) by 41–71%, probably attributed to the fact that it increased CH4 oxidation potential whereas CH4 production potential was increased to a larger extent. There was little CH4 formed during aerobic incubation, and the produced CH4 was more 13C-enriched relative to that of anaerobic incubation. Assuming δ13C-values of CH4 aerobically produced in paddy soil to be the δ13C-values of residual CH4 after being oxidized, Fox-value still appeared to be 45–68% lower when straw was incorporated. Oxidation fractionation factor (αox) was higher with straw incorporation (1.033) than without straw incorporation (1.025). The δ13C-values of CH4 emitted after cutting of the plants (−50–−43‰) were more positive than those of before (−58–−55‰), suggesting a transport fractionation factor (ϵtransport) was −8.0‰ with straw incorporation and −12.0‰ without straw incorporation. Reasons for this difference may be related to the decrease in growth of the rice crop as a result of straw incorporation. The experiment shows that straw incorporation increases the contribution of acetate to total methanogenesis in paddy soil but decreases it on rice roots, and it significantly decreases the fraction of CH4 oxidized in the field, and expands oxidation fractionation while reducing transport fractionation.
Determining spatial variability of dry spells – a Markov based method, applied to the Makanya catchment, Tanzania
Authors: Fischer B. M. C. , Mul M. L. , Savenije H. H. G.
Published: October 2012

Abstract. With a growing world population and a trend towards more resource intensive diets, pressure on land and water resources for food production will continue to increase in the coming decades. Large parts of the world rely on rainfed agriculture for their food security. In Africa, 90% of the food production is from rainfed agriculture, generally with low yields and a high risk of crop failure. One of the main reasons for crop failure is the occurrence of dry spells during the growing season. Key indicators are the critical dry spell duration and the probability of dry spell occurrence. In this paper a new Markov-based framework is presented to spatially map the probability of dry spell occurrence. The framework makes use of spatially varying Markov coefficients that are correlated to readily available spatial information such as elevation and distance to the sea. This map is then related to the critical dry spell duration, based on soil properties and crop water requirements, to assess the probability of crop failure. The results show that in the Makanya catchment the probability of dry spell occurrence is highly variable in space, even over relatively short distances. In certain areas the probability of crop failure reaches levels, which makes rainfed agricultural practices unsustainable, even close to areas where currently rainfed agriculture is successfully practiced. This method can be used to identify regions that are vulnerable to dry spells, and subsequently to develop strategies for supplementary irrigation or rainwater harvesting.
Linking ENSO and heavy rainfall events over Coastal British Columbia through a weather pattern classification
Authors: Brigode P. , Mićović Z. , Bernardara P. , Paquet E. , Garavaglia F. , Gailhard J. , Ribstein P.
Published: October 2012

Abstract. Classifications of atmospheric weather patterns (WPs) are widely used for the description of the climate of a given region and are employed for many applications, such as weather forecasting, downscaling of global circulation model outputs and reconstruction of past climates. WP classifications were recently used to improve the statistical characterisation of heavy rainfall. In this context, bottom-up approaches, combining spatial distribution of heavy rainfall observations and geopotential height fields have been used to define WP classifications relevant for heavy rainfall statistical analysis. The definition of WPs at the synoptic scale creates an interesting variable which could be used as a link between the global scale of climate signals and the local scale of precipitation station measurements. We introduce here a new WP classification centred on the British Columbia Coastal region (Canada) and based on a bottom-up approach. Five contrasted WPs composed this classification, four rainy WPs and one non-rainy WP, the anticyclonic pattern. The four rainy WPs are mainly observed in the winter months (October to March), which is the period of heavy precipitation events in Coastal BC and is thus consistent with the local climatology. The combination of this WP classification with the seasonal description of rainfall is shown to be useful for splitting observed precipitation series into more homogeneous sub-samples and thus identifying, for each station, the synoptic situations that generate the highest hazard in terms of heavy rainfall events. El Niño Southern Oscillations significantly influence the frequency of occurrence of two Coastal BC WPs. Within each WP, ENSO seem to influence only the frequency of rainy events and not the magnitudes of heavy rainfall events. Consequently, MEWP heavy rainfall estimations do not show significant evolution of heavy rainfall behaviour between Niño and Niña winters. However, the WP approach captures the variability of the probability of occurrences of synoptic situations generating heavy rainfall depending on ENSO and opening interesting perspectives for the analysis of heavy rainfall distribution in a non-stationary context.
A Two-Parameter Ratio-Product-Ratio Estimator Using Auxiliary Information
Authors: Chami Peter S. , Sing Bernd , Thomas Doneal
Published: October 2012

We propose a two-parameter ratio-product-ratio estimator for a finite population mean in a simple random sample without replacement following the methodology in the studies of Ray and Sahai (1980), Sahai and Ray (1980), A. Sahai and A. Sahai (1985), and Singh and Espejo (2003).The bias and mean squared error of our proposed estimator are obtained to the first degree of approximation. We derive conditions for the parameters under which the proposed estimator has smaller mean squared error than the sample mean, ratio, and product estimators. We carry out an application showing that the proposed estimator outperforms the traditional estimators using groundwater data taken from a geological site in the state of Florida.
Evaluation of Morphological and Molecular Diversity among South Asian Germplasms of Cucumis sativus and Cucumis melo
Authors: Zhang Chi , Pratap Arun S. , Natarajan S. , Pugalendhi L. , Kikuchi Shinji , Sassa Hidenori , Senthil Natesan , Koba Takato
Published: October 2012

Cucumber, Cucumis sativus (), and melon, Cucumis melo (), are two common vegetable crops worldwide. The present study evaluated eighteen Cucumis accessions (nine C. sativus and nine C. melo) that were collected from three South Asian countries that have the most diversity of Cucumis. Nine quantitative and twenty-three qualitative characteristics were measured. The values of fruit weight displayed the biggest divergence among the nine quantitative traits and much variation was displayed in twenty-three qualitative traits among eighteen accessions. For eight morphological quantitative traits other than fruit weight, eighteen accessions were divided into three groups by using Principle Component Analysis and K-means cluster analysis. Also, two chloroplast genes rbcL and matK of eighteen accessions were sequenced. Combined sequences were subjected to construct phylogenetic trees by Neighbor-Joining and Maximum Likelihood methods. Topologies of nine melon accessions were same in these two methods and nine cucumber accessions showed difference. The genetic distances among each of C. sativus and C. melo accessions were not high. We conclude that the genetic relationship among the eighteen accessions used in this study is not distant although they display significant morphological variations. The information on novel Cucumis germplasms provided here would contribute to breeding program as well as evolutional study in Cucumis.
Acute, Repeated Exposure to Mobile Phone Noise and Audiometric Status of Young Adult Users in a University Community
Authors: Ana Godson R. E. E. , Ukhun Anthony E. , Shendell Derek G. , Osisanya Patience A.
Published: October 2012

Background. Exposure to noise from mobile devices is suspected to affect hearing. Data are limited, particularly in less developed countries. We assessed noise levels from mobile phones and user audiometric status at University of Ibadan, Nigeria, in an initial cross-sectional study. Methods. Fifty-eight staff and 45 young adult students owning mobile phones were selected. A pretested questionnaire assessed demographics, phone attributes, and predominant ear used for making and receiving calls. Noise was measured in A-weighted decibels. Pure tone audiometry was conducted at varying frequencies. Statistics computed included Chi-square and t-tests. Results. Certain phone brands used by students were commonly reported. More utilized right ears to make or receive calls. Mean reported mobile phone use duration by students was 2.9±1.7 years, lower than among staff, 3.4±1.9 years (P<0.05). There were differences in use of head phones (22.2%, 12.1%) and speakers (51.1%, 15.5%) by students and staff, respectively (P<0.05). Mean measured noise levels of phones when ringing, per user settings, were high 91.9±16.1 dBA (students) and 93.3±10.9 dBA (staff). Audiometry suggested 22.2% students and 28.0% staff had some evidence of hearing impairment. Conclusions. Mobile phones noise levels were high, but exposures though frequent were of short duration. Larger, longitudinal studies are needed on phone use and hearing impairment.
Degradation Pathway for Eplerenone by Validated Stability Indicating UP-LC Method
Authors: Sudhakar Babu Kondru , Madireddy Venkataramanna , Indukuri Venkata Somaraju
Published: October 2012

Degradation pathway for eplerenone is established as per ICH recommendations by validated and stability-indicating reverse phase liquid chromatographic method. Eplerenone is subjected to stress conditions of acid, base, oxidation, and thermal and photolysis. Significant degradation is observed in acid and base stress conditions. Four impurities are studied and the major degradant (RRT about 0.31) was identified by LC-MS and spectral analysis. The stress samples are assayed against a qualified reference standard and the mass balance is found close to 99.5%. Efficient chromatographic separation is achieved on a Waters symmetry C18 stationary phase with simple mobile phase combination delivered in gradient mode and quantification is carried at 240 nm at a flow rate of 1.0 mL min−1. In the developed LC method the resolution between eplerenone and four potential impurities (imp-1, imp-2, imp-3, and imp-4) is found to be greater than 4.0. Regression analysis shows an value (correlation coefficient) of greater than 0.999 for eplerenone and four potential impurities. This method is capable to detect the impurities of eplerenone at a level of 0.020% with respect to test concentration of 1.0 mg mL−1 for a 20 μL injection volume. The developed UPLC method is validated with respect to specificity, linearity and range, accuracy, precision, and robustness for impurities and assay determination.
Utility of First Trimester Ultrasonography before 11 Weeks of Gestation: A Retrospective Study
Authors: Celen Sevki , Dover Necmiye , Seckin Berna , Goker Ufuk , Yenicesu Okan , Danisman Nuri
Published: October 2012

We showed the utility of first trimester ultrasonography before 11 weeks of gestation for antenatal followup. We retrospectively analyzed 1295 records of patients who underwent first trimester ultrasonography (transvaginal/abdominal) in our antenatal clinic in Ankara, Turkey. Maternal age, parity, gestational age, and maternal gestational history were compared with ultrasonographic findings. Patients were divided into 12 groups based on ultrasonographic diagnoses in the first ultrasonographic scan, and called for a control examination within 10 days if the diagnostic findings were abnormal. The data were statistically analyzed using Kruskal-Wallis and chi-square tests. We noted 81.3% patients to have single, viable, intrauterine pregnancies, while 18.7% had abnormal or complicated pregnancies with uterine anomalies, ovarian cysts, fibroids, or subchorionic hematomas. Normal and anembryonic pregnancies had significantly lower median diagnostic period in the control ultrasonography than in the first examination. First trimester ultrasonography before 11 weeks of gestation is valuable in determining pregnancy outcomes.
An Adaptive Approach to Discriminate the Persistence of Faults in Wireless Sensor Networks
Authors: Mahapatro Arunanshu , Khilar Pabitra Mohan
Published: October 2012

This paper presents a parametric fault detection algorithm which can discriminate the persistence (permanent, intermittent, and transient) of faults in wireless sensor networks. The main characteristics of these faults are the amount the fault appears. We adopt this state-holding time to discriminate transient from intermittent faults. Neighbor-coordination-based approach is adopted, where
faulty sensor nodes are detected based on comparisons between neighboring nodes and dissemination of the decision made at each node. Simulation results demonstrate the robustness of the work at varying transient fault rate.
Common Dermatoses in Children Referred to a Specialized Pediatric Dermatology Service in Mexico: A Comparative Study between Two Decades
Authors: Del Pozzo-Magaña Blanca Rosa , Lazo-Langner Alejandro , Gutiérrez-Castrellón Pedro , Ruiz-Maldonado Ramón
Published: October 2012

Background. Skin diseases among pediatric patients differ from those in adults. Epidemiological studies are scarce, and those performed in Mexican population date back thirty years. It is likely that these diseases might have changed their frequency.Material and Methods. Retrospective study in first-time patients referred to a pediatric dermatology service between January 1994 and December 2003. Demographics and diagnosis were recorded and compared with the results of a previous study performed in the same institution.Results. We included 5250 patients (52.55% female, 47.47% male) with 6029 diagnoses. The most frequent dermatoses found were atopic dermatitis (14.59%), viral warts (6.62%), acne (5.53%), pityriasis alba (3.98%), melanocytic nevi (3.85%), xerosis (3.57%), keratosis pilaris (3.19%), seborrheic dermatitis (2.37%), hemangioma (2.26%), and papular urticaria (2.24%). Most dermatoses increased their frequency when compared to the previous study.Conclusion. The frequency of pediatric dermatoses in our institution has changed in the last two decades. Environmental and sociocultural factors and institutional policies might account for these results.
Photocatalytic Reaction of Gas-Phase Naphthalene on Paint- and Sunscreen-Coated Surfaces
Authors: Ashley Nicholas A. , McBride Noelle , Krumholt Jason , Baker Breeana , Valsaraj Kalliat T.
Published: October 2012

The uses of metal oxide nanoparticles in modern paint and sunscreen formulations are widespread. Through materials characterization and kinetic experiments, it is demonstrated that fresh surface coatings of paint and sunscreen photocatalytically degrade gaseous naphthalene. The primary metal oxides are TiO2 in the form of the rutile phase in paint and as anatase in sunscreen formulations. Other metal oxides present are Al2O3 and ZnO. Several organic fillers that are photochemically active are also present in paint and sunscreen samples but are unidentified. Reaction rate constants increased with increasing air relative humidity, due to the production of surface hydroxyl radical, and decreased with increasing coating thickness, due to mass transfer limitations. Photocatalytic degradation on these freshly generated surfaces is observed to be fast, with naphthalene half-lives shorter than 30 minutes. This work demonstrates that large, semivolatile organic compounds can react photochemically on freshly generated paint- and sunscreen-coated surfaces and may impact air quality in both indoor and outdoor environments.
Minimizing Chloride Interferences Produced by Calcium Chloride in the Determination of Cd by Graphite Furnace Atomic Absorption Spectrometry
Authors: Waterlot Christophe , Douay Francis
Published: October 2012

Cadmium concentrations in CaCl2 extracting solutions at various concentrations were determined by graphite furnace atomic absorption using two background correctors: the deuterium and the high-speed self-reversal background correction systems. Under- and overestimation of the Cd absorbance signals in CaCl2 solutions were observed for concentrations greater than 0.005 M using the deuterium lamp while no important effect was observed using the other background correction system. The analytical performance of the spectrometer for the determination of Cd was studied in 0.01 M CaCl2 solution and single extractions were performed using reference materials and contaminated soil samples. Cadmium was determined using the two background correction systems and a third method, which consists of the use of the deuterium lamp without any chemical modifier, was added to the study. The results showed that the third method was unable to determine Cd concentrations in the CaCl2 solution due to the presence of extractable arsenic and iron. For solutions without any dilution or diluted with a very low dilution factor, the CaCl2-extractable Cd concentrations measured using the deuterium lamp were systematically below those found using the high-speed self-reversal method. These differences were explained by the presence of chloride ions in the atomization step.
Depression in Multiple Sclerosis: A Review of Assessment and Treatment Approaches in Adult and Pediatric Populations
Authors: Skokou Maria , Soubasi Evanthia , Gourzis Philippos
Published: October 2012

Multiple sclerosis is a chronic demyelinating disease affecting one million people worldwide, with a significant burden of psychiatric comorbidity. Depression is the commonest psychiatric manifestation but still remains largely underdiagnosed and undertreated. The present work reviews current knowledge on diagnosis, assessment, and somatic and psychotherapeutic treatment interventions for depression in adult and pediatric populations of patients with multiple sclerosis.
Suboptimal Coherent Radar Detection in a -Distributed Clutter Environment
Authors: Weinberg G. V.
Published: October 2012

The -Distribution is an important clutter model for high-resolution radar sea clutter returns obtained at X-band. The Neyman-Pearson optimal multilook detector has been derived recently, as
well as the generalised likelihood ratio test suboptimal detector. Both
these detectors are dependent on the modified Bessel-function of the
second kind. This paper suggests a suitable suboptimal approach,
using a well-known Bessel identity, eliminating the Bessel function dependence. This produces a computationally simpler detection scheme,
whose performance is analysed using clutter parameters based upon
real X-band radar returns.
Reasoning with Time Intervals: A Logical and Computational Perspective
Authors: Sciavicco Guido
Published: October 2012

The role of time in artificial intelligence is extremely important. Interval-based temporal reasoning can be seen as a generalization of the classical point-based one, and the first results in this field date back to Hamblin (1972) and Benhtem (1991) from the philosophical point of view, to Allen (1983) from the algebraic and first-order one, and to Halpern and Shoham (1991) from the modal logic one. Without purporting to provide a comprehensive survey of the field, we take the reader to a journey through the main developments in modal and first-order interval temporal reasoning over the past ten years and outline some landmark results on expressiveness and (un)decidability of the satisfiability problem for the family of modal interval logics.